Anal. Chem. 1994, 66, 360R-427R
Dynamic Electrochemistry: Methodology and Application Michael D. Ryan
Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53233 Edmond F. Bowden
Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695 James Q. Chambers'
Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996 Review Contents Books and Reviews Mass Transport Microelectrodes Hydrodynamic Methods Analytical Voltammetry Methodologies Stripping Voltammetry Catalytic Methods Derivatization Methods .Analytical Use of Micelles Pulse and Sweep Methods Metal/Ligand Complexation Studies Chemometric Approaches Heterogeneous/Homogeneous Kinetics Electron-Transfer Theories Heterogeneous Kinetics Homogeneous Kinetics Double-Layer Studies Adsorption Studies Surface Electrochemistry Theoretical Aspects Mercury Electrodes Carbon Electrodes Single Crystal Surfaces Surface Imaging Techniques Polycrystalline Electrodes Miscellaneous Electrodes Modified Electrodes Charge Transport in Polymer Films Electrocatalysis at Modified Electrodes Ion-Exchange Polymer Film Electrodes Ionophore Films Redox Polymer Films Electrochromism and Pattern Formation in Polymer Electrodes Conducting Polymer Electrodes Self-Assembled Monolayers Other Modified Electrodes Bioelectrochemistry Books and Reviews Small Molecules of Biological Importance Protein Electrochemistry Enzyme Electrodes Polynucleotides and Nucleic Acids In Vivo and Cellular Electrochemistry Immunological and Recognition-Based Electrochemistry
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Miscellaneous Bioelectrochemical Studies Characterization of Redox Reactions Electron-Transfer Mechanisms Organic Electrochemistry Organometallic Electrochemistry Inorganic Electrochemistry Activation of Small Molecules Electrosynthesis Micelles and Surfactants Spectroelectrochemistry Instrumentation
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This article reviews the literature of electroanalytical chemistry in the period between December 1991 and the end of November 1993. An attempt was made to minimize the gap in the coverage between this and the previous Dynamic Electrochemistry review in Analytical Chemistry ( A I ) . The focus of this review is on fundamental advances and practical applications of electrochemistry that pertain to electroanalytical chemistry. Topics covered include ultramicroelectrodes, analytical voltammetry, electrode kinetics, surface electrode phenomena, modified electrodes, bioelectrochemistry, characterization of inorganic, organic, and organometallic redox couples, spectroelectrochemistry, and instrumentation. The subject is of course quite broad and the divisions overlap. It is perhaps easier to indicate topics not covered in detail. Applications where there is no net current flow, e.g., potentiometric sensors, have traditionally been covered elsewhere in this review issue. There is not a separate section on photoelectrochemistry in the present review, although citations to articles relating to this topic can be found throughout the review. For the most part, articles were excluded that dealt with exotic electrode materials or media where the emphasis was not electroanalytical in nature. Industrial electrochemistry, fuel cells, and battery applications were also omitted from the coverage. The literature cited below was selected by scanning Citation Index, C A Selects: Electrochemical Reactions, C A Selects: Analytical Electrochemistry, and our personal reading of the literature. The coverage is not exhaustive, but is intended to highlight important developments and activity. A. BOOKS AND REVIEWS Three accounts of a historical nature on square-wave and pulse voltammetry have appeared, in part commemorating 0003-2700/94/0366-0360$14.00/0
0 1994 American
Chemical Society
Mlchael D. Ryan is Associate Professor of Chemistry at Marquette University. I n 1969 he receivedhis B.S. degree from the University of Notre Dame and in 1973 he was awarded a Ph.D. from the University of Wisconsin, Madison. Beforejoining the faculty of Marquette University in 1974, he served as Lecturer at the University of Arizona. His current interests include the study of indirect reduction of nitrite, nitric oxide, and sulfite reductases and the kinetics of electron-transfer reactions of biological compounds. Edmond F. Bowden is currently an associate professor in the Department of Chemistry at North Carolina State University and a member of the Biotechnology Faculty. After earning a B.S. degree in aerospace engineering at Syracuse University in 1970, he spent several years working in the aerospace and chemical industries before returning to school. He obtained his Ph.D. at Virginia Commonwealth University in 1982 under the guidance of Fred M. Hawkridge and then held a postdoctoralappointment at the University of Minnesotawith John F. Evansbefore moving to NCSU. His. research interests include interfacialbioelectrochemistry,biologicalelectron transfer and bioenergetics, enzyme electrodes for bioanalysis, and electroactive monolayers. James Q. Chambers earned his A.B. degree in chemistry from Princeton University in 1959. His graduate work under the direction of Ralph N. Adams was conducted at the University of Kansas, where he received the Ph.D. degree in 1964. The research interests of Prof. Chambers are in the general area of electroanalyticalchemistryandare focused primarily on understanding and characterizingelectrodereactionsinvolvingorganic, polymeric, and biologically importantcompounds.
the original publication of Barker 40 years ago (A2-A4). Osteryoung also makes a passionate case for the advantages and virtues of pulse voltammetry in an Accounts of Chemical Research article (A5). Of practical value is the IUPAC commission on electroanalyticalchemistry review on the effects that arise in pulse voltammetry when adsorptionof the reactant is significant (A6). Several monographs or reviews have appeared recently that would make suitable reading for beginning students at various levels. Koryta has written a short introduction to ionic solutions, electrochemistry, and membrane phenomena that emphasizes concepts and is nonmathematical in nature (A7). A practical treatment of classical polarography also avoids mathematical detail (A8). Run0 and Peters have written an undergraduate level introduction to concepts involving electrode potentials (A9). At the graduate level, the monograph by Gileadi on electrodekinetics is especially noteworthy (AZO). This text does a remarkable job of covering the fundamental concepts of electrode kinetics as well as presenting clear introductory descriptionsof modern techniques, experimental details, and applications to batteries, fuel cells, corrosion, and electroplating. A number of impressiveedited compilations of chapters on topics related to some aspect of electrochemical science have been published in the last two years. Before detailing these,
we will note the extensive, multiauthor review on the current state of understanding and research on the electrode/ electrolyte interface by Bard et al. (A2 2). This report focuses on new experimental capabilities and outstanding issues in three areas: structural characterization, dynamics, and materials aspects of the electrode/electrolyte interface. Elsewhere, Bard has speculated on future directions of electrochemistry in a provocative article (A22). Areas mentioned included UMEs and unusual media, scanning probe microscopies, and molecular biology. Three volumes of Modern Aspects of Electrochemistry have appeared ( A 2 3 4 2 5 ) . Volume 25 has chapters on hydrogen ingress in metals, charge transfer across liquid/ liquid interfaces, dc techniques for measurement of corrosion rates, ellipsometry, and electrical breakdown in liquids. Volume 23 contains chapters on ion and electron transfer across monolayers of organic surfactants, determination of current distributions by Laplace transformation, cathodic protection engineering,semiconductor/metal cluster surfaces, and electrical breakdown in anodic oxide films. Continuing with the eclectic nature of this series, Volume 24 treats nerve excitation, membrane energy transduction, the chlor-alkali process, bioelectrochemical field effects, electronic factors in charge-transfer reactions, and electrodeposition of metal powders with controlled particle grain size and morphology. In similar manner, a compilation with a high-sounding title (A26) contains chapters on the double layer, in situ spectroscopic examination of electrodes, electrode kinetics, organic electrochemistry, high-temperature electrochemistry, corrosion, and others. The most recent volume of Advances in Electrochemical Science and Engineering (A2 7) contains four chapters: Trasatti on electrocatalysis of the HER, Hammou on solid oxide fuel cells, Richmond on second harmonic generation at single crystal electrodes, and Deslouis and Tribollet on flow modulation techniques. Lipkowski and Ross have edited two volumes of generally high caliber reviews relating to fundamental surface science at electrode interfaces (A28, A29). The first, which deals with adsorption of molecules, contains several chapters on radiochemical and spectroscopic characterization of adsorbed layers. The second, which is a collection of major reviews on the structure of the metal/ electrolyte interface, includes chapters by vacuum surface experimentalists, theorists, and electrochemists. Among the latter are reports by Ross on surface crystallography, Kolb on surface reconstruction, and Soriaga on molecular adsorption a t single crystal electrodes. Omitted from the previous Analytical Chemistry review ( AI ) was mention of a compilation that contained chapters on the structure of halides and small organic molecules on metal surfaces by Hubbard, on heterogeneous catalysis of substitution reactions by Spiro, on the kinetics of crystallization of solids from aqueous solution by House, and a general introduction to corrosion of metals by Hammond (A20). In yet another volume one can learn about the semiconductor/electrolyte interface, electrode potentials, and energy scales, the application of STM to electrochemistry, adsorption and electron transfer at interfaces, and various electrochemical aspects of biomembranes (A22). Two reviews of solvent effects on electron-transferreactions have appeared (A22, A23). Weaver’s article is mostly Analytical Chemistry, Vol. 66, No. 12, June 15, 1994
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nonmathematical and emphasizes concepts. Galus summarizes theoretical treatments of the reaction rates for both soluble couples and amalgam-forming reactions such as Zn2+/ Zn(Hg). In a review by Saveant of his contributions to our understanding of dissociative electron-transfer reactions, he outlines criteria for distinguishing between stepwise and concerted mechanisms in electrode reactions ( A 2 4 ) . Trasatti has reviewed recent theory on the adsorption of organics on electrode surfaces (A25), and Parsons and Ritzoulis critically compare experimental results for adsorption on stepped surfaces of Pt and Au single crystal electrodes (A26). In the latter article, the evidence for the assignment of voltammetric peaks in the hydrogen region to hydrogen atom adsorption on steps of surface unit cells was clearly summarized. A thorough review of UHV techniques as applied toobtain atomic level information about the electrode interface at single crystal electrodes has been provided by Soriaga (A27). This treatment is suitable for a graduate student level introduction to the area. A substantial analysis of the kinetics of oxygen reduction at solid electrodes in aqueous solution has been written by Appleby (A28), and a book has appeared on the electrochemistry of surfaces from the critical perspective of Professor J. O’M. Bockris (A29). Catalysis of the hydrogen ion reduction by metal surfaces has been briefly reviewed (A30). An IUPAC Commission report has appeared that compiles kinetic parameters on the C12/C1- electrode reaction (A31). Also the IUPAC Commission report dealing with the measurement of real surface areas has been published a second time (A32). This report describes 15 methods, 11 in situ and 4 ex situ, in detail. A variety of ancillary techniques for the study of electrode processes are treated in a recent volume; included are chapters on ellipsometry, inferometric methods, SERS, Mossbauer spectroscopy, photothermal deflection spectroscopy, X-ray absorption and neutron scattering, impedance spectroscopy, and others ( A 3 3 ) . An introduction to STM and AFM with emphasis on basic theory and practicalities has appeared that discusses the application of these techniques to in situ electrochemistry (A34). Scanning tunneling spectroscopy, which can map the surface electronic structure with atomic resolution in the best scenario, was also addressed. Buttry and Ward have written perhaps the most authoritative of several recent reviews on electrochemical quartz crystal microscopy (EQCM) (A35). Hillman et al. also reviewed the QCM technique with emphasis on the detection of mobile species transferred during the redox switching of polymer films (A36). A review of electrochemical mass spectroscopy (ECMS) contains some excellent examples of the use of a thermospray LC/MS interface with an electrochemical cell (A37). Solution IR spectroelectrochemistry has also been briefly reviewed (A38). Recent applications of spectroelectrochemistry have been described in a report that focuses on the redox chemistry of thin-film interfaces, e.g., inorganic semiconductors, oxide and chalcogenide films on native metals, dye-modified electrodes, conducting polymer films, and others (A39). Volume 18 of the Bard series, Electroanalytical Chemistry, contains reviews on electrochemistry in microheterogeneous fluids by Rusling, charge transport in polymer-modified 362R
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electrodes by Inzelt, and SECM by Bard et al. ( A 4 0 ) . Inzelt has also reviewed polymer film electrodes elsewhere ( A 4 1 ) . Microelectrodes have been covered thoroughly in a publication of the proceedings of a NATO advanced study institute that contains articles from most of the laboratories which have contributed to the development of this area (A42). The authoritative review by Heinze on this subject is also recommended ( A 4 3 ) . The latest in the Techniques in Chemistry series deals with the molecular design of electrode surfaces. Nine individual chapters written by active mod squad researchers cover subjects such as adsorption on single crystal electrodes, various aspects of redox polymer electrodes, and self-assembled monolayers. The volume, which includes more than 1400 references, is tightly edited by Royce Murray, who contributed a highly recommended overview chapter (A44). Reviews in this area have appeared elsewhere (A45-A49). The articles by Forster and Vos on the theory and applications of modified electrodes (A45) and by Zagal on electrocatalytic processes at metallophthalocyanine surfaces (A46) are nicely done. Several reviews treat subjects that strongly overlap electrochemistry and the amorphous, but fashionable, area of materials science. The chapter on processable conducting polymers in a compilation containing five chapters on nonlinear optics and conducting polymers is especiallynoteworthy (A50). Mirkin and Ratner have produced a provocative treatise on molecular electronics (A.71) and electrochemistry at high-T, superconducting working electrodes, an area where electrochemistry can contribute to both fabrication and characterization, is the subject of a report (A52). Other reviews treated the structure and physical properties of PEO-type polymer electrolytes (A53) and the electrochemical synthesis and properties of conducting polymers ( A 5 4 ) . The article by Curran et ai. narrowly focused on the various methods by which polypyrrole can be employed as a support for electrocatalytic materials or substituent groups ( A 5 5 ) . Recent work toward the development of practical biosensors has been reviewed from several different viewpoints (A56A62). These devices are generally based around a redox enzyme coupled with a molecular mediating species entrapped in an interfacial matrix of some kind. Both amperometric and potentiometric detection can be employed. The review of Alvarez-Icaza and Bilitewski gave a good summary of design parameters and their optimization (A56). Thearticleof Wring and Hart (A61) concentrated on the chemistry of the modification of carbon-based substrates for these devices,while that of Hilditch and Green had a practical bent describing disposable electrochemical biosensors in or near to commercial production (A62). Ewing et al. have reviewed progress on the difficult problem of analyzing the contents of single nerve cells with emphasis on in vivo electrochemistry and EC detection for capillary electrophoresis where the Penn State group has made major contributions (A63). Several works have appeared that concern more classical analytical voltammetry. These include a little monograph by Smyth on the voltammetry of biologically important molecules (A64)and reviews of analytical voltammetry theory by Cassidy (A65),adsorptive cathodic stripping voltammetry by van den Berg (A66), the reduction of metal complexes on Hg by
Tur’yan (A67), and instrumentation for voltammetry by Barisci et al. (A68). In addition, a bookon cyclicvoltammetry has been recently advertized (A69). In the realm of organic electrochemistry, several important books or reviews have been published in recent years. A revised and expanded third edition of the Manual Baizer opus has appeared (A70). To complement this work, a book based on a symposium in honor of Manny Baizer contains 48 chapters organized under the following headings: Mechanism; Reduction; Oxidation; Mediated Reactions; Biochemical, Biomass and Natural Products; Modified, Sacrificial/Consumable Electrodes; Electrogenerated Bases; Film-Forming Electropolymerization; and Ion-Exchange (A71). Professor Shono has written a brief text that features experimental details for 150 electrochemical transformations of specific compounds (A72). Niyazymbetov and Evans have summarized the use of carbanions and heteroatom anions in electroorganic synthesis (A73). Recent examples of in situ generation of anions and anodic oxidation of anions are given. Commercial applications are emphasized in a brief review of the use of sacrificial anodes in synthetic electrochemical processes involving C 0 2 (A74). The problem of C 0 2 reduction has also been treated from several different angles in a collection of chapters by different authors (A75). Other reviews have appeared on the electrosynthesis of polymers with emphasis on intermediates (A76) and on the electrochemistry of chlorophyll (A77). Two excellent treatments of important topics have been produced by authorities in their respective fields. Wayner and Parker have provided an Accounts of Chemical Research article on the thermodynamic relationships between bond dissociation energies and redox potentials of the derived radicals and their corresponding ions (A78). A clear description is given here of the way to incorporate voltammetric peak potential data into the thermodynamic cycles. Koval and Howard have presented a thorough review of electron transfer at semiconductor electrode/liquid electrolyte interfaces (A79). While the emphasis of this review is on research advances since 1985, it also serves well as a lucid introduction to the terms and fundamental concepts of a complex subject. Gratzel has given an account of his research on photoelectrochemical energy conversion using a “molecular machine” based on thin films of colloidal Ti02 particles that are sintered together to allow for charge carrier transport (A80, ,481). The phenomenon of room-temperature photoluminescence from porous Si was reviewed in comprehensive fashion (A82),and a review of photoemission at metal/electrolyte interfaces includes a discussion of the cathodic generation of solvated electrons (A83). An issue of Electrochimica Acta was devoted to new trends in photoelectrochemistry (A84). Finally, two issues of the Journal of Electroanalytical Chemistry have accounts of the scientific careers and useful complete lists of their publications for two stalwarts of physical electrochemistry: Professors Brian Conway and John O’Mara Bockris in Vols. 355 and 357, respectively (A85, A86). 6. MASS TRANSPORT Microelectrodes. Theory. The intense activity in the area of microelectrode theory has lessened in the last few years. Applications of UMEs have mushroomed, however, and there
have been some important and useful papers published that deserve mention here. In the latter category, Mirkin and Bard have presented a theoretical analysis of quasi-reversible steady-state voltammograms that allows extraction of the kinetic parameters (ko and a ) from a single i-E curve without independent determination of the Eo’value ( B I ) . They gave extensive tables for the wave shape parameters, E114 - E112 and E112 - E3149 that correlate with given sets of kinetic parameters. Correlation tables were given both for the case of uniformly accessible electrodes, such as a RDE and an U M E hemisphere, and for a U M E disk. Another procedure that appears to be easy to implement for the determination of heterogeneous rate constants from CV peak separation data is that of Lavagnini et al., which only requires intermediate diffusion control such that peak currents are evident in the CVs (B2). Exact formalism for the ac impedance of spherical, cylindrical disk, and ring UMEs was developed (B3). Real and imaginary components of the impedance, assuming uniform flux at the electrode surface, were tabulated as a function a2w/D, a dimensionless quantity where a is the characteristic dimension of the UME, w is the frequency, and D is the diffusion coefficient of the Ox/R couple. Linear sweep voltammograms obtained at ring electrodes were calculated over 9 orders of magnitude sweep rate and compared to experimental results (B4). Calculation of the theoretical voltammograms required the value of a dimensionless parameter, y = (R2 + R1)/2(R2 - Rl), where R2 and R1 are the outer and inner ring radii, respectively. Oldham has continued his penetrating theoretical examination of microelectrode behavior in a very general treatment of steady-state voltammetry at UMEs of arbitrary shape (B5). H e showed that the steady-state current depends on three factors: the electrode area, an accessibility factor, and a heterogeneity function. A universal equation is given for the i-E relationship. A sophisticated integral equation approach was used by Bender and Stone to treat steady-state mass transport to microelectrodes (B6). They gave a numerical solution procedure for calculation of the surface flux that is applicable to the general case of an arbitrarily shaped planar electrode, including both surface and bulk catalytic regeneration reactions. Multidimensional integral equations were used in another mathematically sophisticated approach to UME diffusion problems (B7, B8). The approach was stated to have considerable advantage over the conceptually simpler finite difference and finite element digital simulations in terms of computer requirements and execution time. UME configurations considered were microdisks embedded in an insulating plane of infinite or finite extent, microbands, the SECM problem, and an array of inlaid planar electrodes of arbitrary shape. Brodsky et al. presented closed-form solutions of the diffusion kinetic equation for individual or arrays of UMEs that were based on a “zero range approximation” (B9). They achieved excellent agreement between calculated and experimental collection efficienciesusing literature data. Conformal mapping procedures for the digital simulation of diffusion at a microdisk have been optimized and improved (BI0, SI]). Analytical Chemistry, Vol. 66,No. 12, June 15, 1994
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Oldham has also generalized his treatment of steady-state voltammetry in the absence of supporting electrolyte (SE) in two important papers (B12, B13). In the first, theory was developed for three classes of voltammograms: “sign-retention voltammograms”,where Ox and R have the same sign; “charge neutralization voltammograms”, where a neutral product is generated; and “sign reversal voltammograms”, where Ox and R have opposite signs. In the first two situations, plateaus will exist in the limiting current region, while in the latter the current was predicted to increase in a linear fashion with potential. For the charge reversal CVs, there is a marked dependence on trace amounts of supporting electrolyte (B12). The second paper gave steady-state voltammetry theory at a hemisphere UME for any degree of supporting electrolyte excess relative to the concentration of the reactant. Reversible, quasi-reversible, and irreversible i-E curves can be calculated from the equations given and representative examples of different cases are worked out. The criteria presented by Myland and Oldham should give theexperimentalist new tools for characterizing electrode reactions by variation of the S E concentration. The theory, however, is developed by assuming that there is no adsorption of Ox or Ron the electrode surface. Myland and Oldham also derived the support ratio, [SEI/ [reactant], needed to ensure that thelimiting current is within 2% of iIimfor infinite excess SE, and to ensure that E1p is likewise displaced by less than 1 mV. Convective mass transport at macroelectrodes, i.e., RDEs, may be treated in a way that exactly parallels the general theory of this paper with simple algebraic replacements (B13). Two important papers address problems that will arise for so-called nanodes, electrodes with characteristic dimensions on the order of nanometers. Smith and White calculated i-E curves for very small electrodes based on a numerical solution of the Nernst-Planck and Poisson equations (814). They showed that the double-layer electrical field can markedly affect the currents, even in the presence of a large excess of S E and even for neutral reactants. Under conditions where the double layer and the depletion layer have similar dimensions, and where charge separation in the depletion region occurs due to ionic flux, the assumption of electroneutrality is not generally valid. Another possible artifact for very small electrodes is the problem of incomplete adhesion or cracks between the electrode surface and the insulating sheath. This can create a “lagoon” of electrolyte solution behind a pinhole. Oldham modeled this situation with a geometrically well-defined lagoon and solved Fick’s equation in elegant style (B15). The limiting currents, the time to reach steady state, and the kinetic parameters extracted from the CVs all are significantly altered. These lagooned electrodes, however, do behave as UMEs and can have some analytical virtues, e.g., more reversible behavior phenomenologically. Several articles have considered coupled homogeneous chemical reactions at UMEs (B16-B21). The EC, EC’, ECE, and DISPl reaction schemes were incorporated into simple theory using a steady-state reaction/diffusion layer concept ( 8 1 7 ) . Bond et al. have applied UMEs for the determination of Eo’values and kinetic parameters for a Cr carbonyl complex that participates in a square scheme (B22). This paper also described a neat procedure for correction of the iR, drop 364R
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involving the simultaneous measurement of the difference current between electrolyte solution in the presence and absence of analyte. Other miscellaneous applications include the chronoamperometric determination of the absolute concentration of a well-behaved electroactive species at a microwire UME (B23). The procedure rested on the Aoki equation, whereby the concentration is a function of the intercept and slope of the it112/area vs t ’ I 2 curve (and the electrode radius and n value). A procedure was given by Wikiel et al. for measurement of the stability constants of metal complexes by analysis of the anodic dissolution reaction of a metal UME operating in a normal pulsevoltammetry mode ( 8 2 4 ) . Pulse techniques applied to dissolving metal UMEs such as Cu render the entire voltammetric wave accessible due to the reduced iR drop and double-layer capacity of the UME ( 8 2 5 ) . A Monte Carlo method of modeling the random motion of particles was employed to simulate diffusion noise at a UME (B26). Experimental Aspects. Procedures for the fabrication of UMEs have been pretty well worked out in recent years. Nonetheless, useful tidbits can be gleaned by perusal of experimental sections of the myriad of articles on UME applications. The reader is to be warned that surveying the literature in this manner is hit and miss. A careful study was carried out on methods to maximize the S / N ratio for the detection of dopamine using Nafioncoated carbon fiber UMEs (B27). Sources of noiseconsidered included Johnson noise from the feedback resistor in the current follower, waveform generator noise, line noise, and physiological noise in in vivo measurements. In this study dopamine was readily detected at a 100 nM concentration with a S/N ratio of 25 using fast-sweep voltammetry. Reasonable CVs of dopamine were obtained using very small carbon fiber UMEs (overall dimensions of 400 nm) that had been insulated with a phenol-allylphenol copolymer (B28). A simple procedure of sealing UME carbon fibers or wires in polypropylene has been published (B29). On-line iR, compensation was employed to perform CV at sweep rates up to 11 kV/s using 7-pm carbon fibers (830). Peng et al. have described fabrication and electrochemical activation of carbon fiber UMEs for the in vivo determination of neurotransmitters (B31). Photolithographic methods were used to make carbon IDAs with 3-pm-wide fingers separated by 2 pm of Si3N4 insulation (B32). The carbon, which was vapor deposited by pyrolysis of a perylenetetracarboxylic dianhydride, exhibited an electrochemical behavior similar to that of glassy carbon. Wrighton’s group, which has pioneered the use of photolithography to make UME arrays, has used surface spectroscopy to characterize an array consisting of six or eight individually addressable Au or Pt UMEs on a Si3N4 substrate (B33). The experimental details for carbon-based enzyme electrodes often involve state-of-the-art fabrication techniques. For example, amperometric enzyme electrodes were prepared using extremely thin (35-50 nm thick) carbon films prepared by the pyrolysis of spin-cast polyacrylonitrile (B34). The enzymes were entrapped on the nanobands by electropolymerization of 1,2-diaminobenzene in the presence of the enzyme. Mention is also made of the elegant surface
modifications of carbon fiber UMEs by Kuhr and co-workers (B35,B36). Enzyme electrodes were made using TTF-TCNQ salt deposited in the recessed tips of 7-pm carbon-fiber UMEs. The conducting salt mediated the redox chemistry of flavoenzymes attached to the surface via the glutaraldehyde method (837). Platinum and gold UMEs were prepared by the direct electroreduction of Au(II1) and Pt(IV/II) onto the tips of carbon fiber electrodes that had been coated with an insulating polymer (B38). Also, Ewing’s group has used Au ring UMEs prepared by electrodeposition of Au onto carbon rings (B39). A little paper on the measurement of k” values for the Fe(CN)63-/4- couple has some interesting details (B40). The presence of millimolar amounts of cyanide in 1 M KCl solution was found to stabilize the response. Pretreatment by either polishing with an alumina slurry containing KCN or by laser activation yielded k” values in the range of 0.5 cm/s. Particulars were given for construction of U M E arrays using Buckbee-Mears minigrids (B41). The epoxy-potted electrodes were polishable and had relatively regular spacings (which were the cross sections of the minigrid wires). The morphology of micropit arrays formed by electrochemical etching of carbon fiberlepoxy electrodes was characterized by bullet-shaped tips (B42). A proof-of-principle submicrometer galvanic cell consisting of STM-deposited Cu and Ag pillars on a HOPG surface was demonstrated (B43). Atomic microscopy showed that the 70-nm cell discharged when immersed in a plating solution. Martin and his troops have been busy making and characterizing arrays of metal cylinders deposited in the pores of alumina microporous template membranes. They have prepared recessed gold disk array electrodes, for example, with very deep 200-nm-diameter microholes (B44). In another study, they showed that the color of arrays of Au cylinders with nanometer dimensions could be changed by variation of the aspect ratio of the nanocylinders (B45). Properly prepared arrays were transparent in the infrared region (2000-4000 cm-I) (B46). Also, arrays of CdSe and CdTe microfibrils were fabricated in this manner (B47). Iridium is known to be a good substrate for mercury electrodes. A nice application of anodic stripping square wave voltammetry employed an iridium substrate-based Hg UME where the Ir was etched to a radius of 5-10 pm prior to Hg deposition (B48). Metal ions were determined without deoxygenation, without added SE, and without controlled stirring during the deposition step. The diffusion coefficient of T1” in T1 amalgams was determined by UME chronoamperometric methods (B49). Applications. Even a cursory survey of the current literature reveals that U M E methodology and theory have widened considerably the playing field of electroanalytical chemistry. Several accounts have described UME voltammetry in the absence, or at low ratios, of the SE to analyte concentration where agreement was sought with Oldham’s theory (B50). Drew et al. reported agreement for ratios greater than 0.1, but found that natural convection and the tendency of the generated ions to scavenge ions into the diffusion layer vitiated the theory (B51). For inorganic redox couples of varying charge and Elf2 values, Cooper et al. also reported anomalous behavior in several instances (B52). Lee and Anson
found that the electroreduction of Fe(CN)a3- at carbon and Pt UMEs was markedly suppressed in the complete absence of S E (B53). Reduction of this species, however, could be efficiently mediated by the positively charged M V W + couple. Comproportionation kinetics of the latter system were studied by steady-state voltammetry in solutions of low S E concentration (B54).In an interesting study, Cooper and Bond found adsorption of neutral cobaltocene and passivation of the electrode surface for the (Cp)2C0+/~f-system in CHsCN (B55). At UMEs this gave rise to stochastic processes at negative potentials where cathodic dissolution of the film, as (Cp)2-, is possible. Homogeneous electron-transfer kinetics in monomeric organic liquids such as nitrobenzene were studied by Norten et al. (B56). At Pt UMEs, the second wave for the formation of the NB2- dianion was depressed relative the first wave due to the combined effects of the comproportionation reaction and electrostatic repulsion of the NB’- away from the negatively charged depletion layer surrounding the electrode. Others have looked at the UME voltammetry of nitrobenzenes in low ionic strength aprotic media (B57), and Ciszkowska and Stojek obtained well-defined anodic waves, with a 0.5 n value, for the oxidation of solvent in neat alcohol solution with LiC104 SE (B58). Several studies have employed UMEs at low or wide temperature ranges. Attention is drawn to the low-temperature CVs of the (Cp)2M2+f+f0/-f2-cobaltocene and nickelocene systems in liquid SO2 (B59), the careful kinetic study of the ferrocene couple over the 200-300 K temperature range (BbO), and the temperature-dependent phase transitions and diffusive electron and solute transport seen in polyether “solid-state” solvents (B61). CVs of the Fe3+f2+couple in ice featured surface or thin-layer behavior, indicating the existence of liquid water microphases in contact with the UME surface at temperatures below the freezing point (B62). Modestly fast CVs and chronoamperometry of polyaniline films in contact with H C 1 0 ~ 5 . 5 H z Oat temperatures down to 220 K suggested that the oxidation process involved electrocrystallization phenomena (B63). Voltammetry and chronoamperometry has been performed at pressures up to 8000 bar using Pt microcylinder wire electrodes (B64, B65). A two-electrode cell with a UME coated with redox polymer/enzyme functioned remarkably well in a CO2-based fluid near its critical point (B66). Several more strictly analytical applications of UMEs included studies of the reduction of acids in the presence and absence of S E (B67, B68), ASV of heavy metals in natural waters at Hg UMEs (B69),and a method for thedetermination of the total acidity of various wines (B70). Good results were obtained for analysis of Hg in the absence of S E by ex situ plating of a U M E Pt disk followed by transfer of the electrode to an electrolyte solution for ASV (B71). Very nice CVs of solid-state vanadyl sulfate hydrate were obtained at a carbon disk U M E (B72). U M E voltammetry was carried out in a single drop of solution by Unwin and Bard, who measured the adsorption and ion exchange of H+ on a silicate mineral surface and of methylene blue on HOPG and polycrystalline graphite surfaces (B73). Likewise, Bowyer et al. did electrochemistry involumes as small as 0.05 pL using a three-band array consisting of a Analytical Chemistty, Vol. 66, No. 12, June 15, 1994
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4-pm Pt working electrode, a 100-pm Ag reference electrode, and a 100-pm Pt counter electrode separated by heat-sealing film (B74). In continuing publications, mostly from the Texas laboratory of Bard and co-workers, the versatility of the scanning electrochemical microscopy (SECM) technique has been demonstrated. Wipf and Bard made significant improvement in the technique by employing small-amplitude tip-position modulation in combination with lock-in detection of the signal ( B 7 5 ) . This gave unambiguous indication of whether a surface was conducting or insulating and markedly improved the contrast between those surfaces. In another study, it was shown that information on the tip shape could be obtained from the SECM response at a well-defined flat surface (B76). This is important for very small UMEs where conical-shaped electrodes are much more easily fabricated than insulated UME disks. SECM theory was developed for the determination of fast heterogeneous kinetics from steady-state currents (B77, B78). The method, which involves determining the current as a function of potential for fixed values of d / a , where d is the separation between the scanning tip of radius a and the conductive surface, should permit rate constants up to 10-20 cm/s to be measured. The technique was applied to the measurement of the rate constants for the ferrocene+/O and C& couples (B78,B79). Also SECM, operating in the feedbackand generation/collection modes, was applied to the measurement of rates of chemical reactions coupled to electrontransfer steps for the electrodimerization of activated olefins (B80). Simulation of the redox kinetics in the tipsubstrate gap was performed in conjunction with SECM to image the redox enzyme glucose oxidase immobilized on nonconducting substrates such as nylon, hydrogel membranes, or a L-B film (B81). An antimony UME was used with the SECM apparatus as a potentiometric sensor for hydrogen ion activity (B82). General theory was developed and applied to give pH images around a Pt electrode during the reduction of water, a corroding AgI disk in cyanide solution, a disk of immobilized urease hydrolyzing urea, and other systems. The SECM technique was used to characterize solid films of AgBr (B83). The diffusion coefficient of bromide ion in the AgBr matrix was deduced from the tip current transients produced when the tip/substrate pair was pulsed in a thin-layer electrochemical mode. SECM has also been employed to map ionic fluxes of electroactive species at various porous membranes including mica and mouse skins (B84), to detect proton motion at polyaniline film electrodes (B85),to monitor ion release from protonated poly(viny1pyridine) films (B86),and to characterize a 200-nm-thick polymer film (B87). Surface diffusion and desorption processes are readily handled by SECM. In this application, the probing tip, biased at a potential where the adsorbate is electroactive, yields a current that is a function of the rate of diffusion through solution, the adsorption/ desorption kinetics, and the rate of surface diffusion (B88). The approach was illustrated by detection of H+adsat rutile(001) and aluminosilicate surfaces. In vivo electrochemistry under physiological conditions, which was the original motivation for U M E voltammetry, has provided some of the most impressive applications of UMEs in analytical chemistry. The detection of the release of 386R
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catecholamines at the femtomole level from individual adrenal medullary chromaffin cells continues this tradition (B89). Interestingly, both cells that released only epinephrine and cells that released a mixture of epinephrine and norepinephrine were identified. Wightman’s group have used UMEs to monitor the flux of catecholamines from other biological cells during exocytosis (B90). The process was analyzed in terms of diffusive mass transport from a point source. Ewing’sgroup has used platinized carbon microring electrodes to monitor 0 2 concentrations and to perform multiple pulsevoltammetry in single neuron cells of their favorite pond snails (B91,B92). Oxidation currents have also been measured due to generation of superoxide anions at a carbon UME in contact with a single biological cell (B93),and a Pt on graphite UME was used to monitor oxygen efflux from illuminated algae protoplasts (B94). The release of NO from a single cell was detected with a carbon fiber UME coated with a polymeric porphyrin/ Nafion composite film (B95). Adams and co-workers used Nafion-coated carbon fibers to detect norepinephrine release and to profile glutamate-evoked ascorbic acid release in the brains of freely moving rats (B96,B97). Impedance analysis of 100-pm Pt electrodes covered with biological cell cultures indicated the formation of pores in the cell membranes upon application of small applied voltages (B98). UME arrays have been employed in innovative fashion. Electrochemical luminescence, generated by a radical cation plus radical anion annihilation reaction, was examined at double-band UME arrays both experimentally and theoretically using conformal mapping transformations (B99). For reversible systems the depletion effect in differential pulse voltammetry is minimized for an interdigitated array (IDA) working electrode operating in the feedback mode (BIOO). An IDA electrode, also operating in the collection mode, was shown to be a sensitive detector under conditions compatible with an enzyme immunoassay (BIOI). Volumes as small as 800 nL were successfully handled in this study. A clever application of an IDA incorporated an electrochemical coulometer in series with an IDA in a solution of a reversible redox couple. The coulometric process employed was electrodeposition of a metal, which was followed by ASV analysis allowing determination of the redox couple at the M level (B102). IDAs have been used to measure apparent electron diffusion coefficients in polymeric matrices: good examples are the study by Nishihara et al. of poly(ethy1eneoxide) (8103) and the redox switching of poly(pyrro1e) films (B104). Several papers have addressed theoretical aspects of various array geometries. These include a treatment of the overlap of diffusion layers at microband arrays (B105),cylinder arrays closely aligned parallel to a planar electrode (B106),and dualcylinder UMEs in parallel operating in a biamperometric mode with a small imposed voltage difference (B107). The latter theory was applied to the titration of ascorbic acid with ferricyanide. Frequencies as high as 20-30 kHz were used for the generation of electrochemical luminescence by square-wave generation of the radical ions at UMEs (B108). A lower limit on the ion-annihilation rate constant for diphenylanthracene of 2 X 1O9 M-’ s-l was determined. Double-band UME arrays have also been used to generate ECL in a steady-state mode of operation (B109).
Hydrodynamic Methods. Rotated Electrodes. Verbrugge has given a theoretical analysis of the RDE convectivediffusion problem for an Ox/R couple that is valid for a wide range of Schmidt numbers and Reynoldsnumbers (BIIO).Thecurrent response was found to be bounded by the Levich equation for large Schmidt and Reynolds numbers and by the stationary disk response for zero Schmidt or Reynolds numbers. Vieil developed a general mathematical treatment of mass transfer that quantifies the transition between stationary convective mass transport and time-dependent accumulation at an electrode surface (BI 11). A mass-transfer rate expression is given that can accommodate a variety of experimental conditions such as fractal geometries and transient behavior at RDEs. Simulation of transient diffusion and migration to a RDE during deposition of a metal film gave information on the current distribution, the effect of inert electrolyte, and the role of disk size (B112). Bartlett and Eastwick-Field have written a particularly cogent analysis of limiting currents at a RDE for a generalized ECE reaction scheme (B113). The effect of rotation rate on U M E array composite RDEs was studied using composite electrodes of gold and graphite particles embedded in Kel-F (BI 14). As expected, significant enhancement of true current density was seen at the array electrode in comparison to solid electrodes; Le., [(i/area),,,,,/ (i/area),,~id] > 1, where the active area is used to calculate the current density. Several researchers have used rotation rate modulation techniques in various studies. The rotation rate step method of Blauch and Anson (B115)was applied to a silver electrode to determine the diffusion coefficients of electroinactive ligands (BI 16). Anodic 0-transfer reactions at several electrodes (Pt, Au, Pd, Ir, and glassy carbon) were studied using a current difference RDE method that diminished the contribution of 0 2 evolution to the observed response (BI 17). A key role for adsorbed hydroxyl radicals was deduced in this study. Engelhardt et al. have presented theory for hydrodynamic square-wave modulation of a rotating ring disk electrode (B118-B120). The method is useful when there are parallel reactions and the ring current of interest is masked by large background currents. In the experiments of Schwartz (B121), the rotation rate of a commercial RDE was modulated by a sinusoidal or by a square root waveform. Fourier transformation then gave the frequency response of the system in a single experiment. Hydrodynamic impedance has also been employed by Deslouis and Tribollet (B122). Papers continue to be published that exploit the power of rotating electrodes in mechanistic studies. Rotating ring disk techniques were used to study the MV2+l+Iosystem (MV is methyl viologen) in aqueous solution, where surface blocking by adsorbed neutral species had to be taken into account (8123). Likewise, Kokkinidis et al. found that electrodeposition of neutral benzyl viologen onto Pt or Hg proceeded by direct nucleation and 3-D growth under mass transport control (B124). Other studies include chronocoulometric measurement of adsorbed intermediates in the oxidation of iodide at a Pt RDE (B125),voltammetry of adsorbed intermediates in the HER (B126), the electrocatalytic oxidation of CN- at a glassy carbon RDE (B127), the mediated reduction of an alkyl halide (BI 28), the detection of the anaesthetic halothane
via oxidation of released B r a t the ring electrode (B129),and measurement of enhanced D values due to homogeneous electron exchange in the RDE voltammetry of Ru-EDTApoly(viny1pyridine) complexes (B130). On the more applied side, the photographic fixation process at a AgCl emulsion disk electrode was followed by monitoring the flux at a ring electrode (B131),and a novel RRDE method was described for the detection of COz expired in breath from a human subject (B132). Compton and Brown have proposed a RDE method to monitor particle size in solution that is based on the enhancement of mass transport in the presence of suspended particles (B133). Others have studied mass-transfer enhancement in a dilute suspension of rotating particles under the influence of shear flow (B134),and Gabrielli et al. treated the ac impedance of fluidized-bed electrodes, both theoretically and experimentally for gold beads in NaOH solution (B135). In the miscellaneous category are papers on the rotating ring cone electrode (B136),mass transfer at the entire surface of a vertical cylinder electrode (B137),the use of an inverted RDE for the study of gas-evolving reactions (B138),and mass transfer at a RDE with external forced convection (B139). Wall Jet and Channel Electrodes. R. G. Compton and his colleagues have continued their sophisticated analysis of wall jet and channel electrodes. As will be noted below in the section on electrochemical detectors for FIA or chromatographic columns, these configurations have real practical significance. The Compton group has presented theory for the transient current response for a simple E step at a WJE (B140) and at the ring in a wall jet ring disk electrode (8141). The theory was experimentally verified in a later study (B142). They also developed theory for CV at a WJE where the electrode is substantially larger than the jet. The theory predicts transitions from steady-state CVs at slow sweep rates to peakshaped response at fast sweep rates (B143). The roleof radial diffusion in the WJE response has been considered in a more recent paper (B144). Compton et al. have presented a general computational approach to calculation of i-E curves at channel electrodes (B145)and, in a related paper, calculated limiting currents for UME band electrodes in a rectangular flow channel under conditions where convection is the predominant mode of mass transport (B146). Tait et al. have also tackled the difficult problem of a U M E disk electrode in a flow channel using finite difference simulation (B147). The effect of electrode size, solution velocity, and channel thickness on the magnitude of the near-steady-state currents and the time required to reach this condition were determined in the latter paper. A treatment of the catalytic EC’ reaction at a flow channel electrode is representative of several articles on coupled chemical reactions under these conditions (B148). A four-element carbon paste array detector, which consisted of different graphite/metal oxide composite surfaces in a wall jet configuration, displayed different electrocatalytic sensitivities toward carbohydrates and amino acids (B149). In another study, the performance of an array W J E assembly was optimized (B150). Flow- Through Electrochemical Detectors. Electrochemical detectors for chromatographic or FIA columns (LCEC) Analytical Chemistty, Vol. 66, No. 12, June 15, 1994
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are routinely employed. Only a fraction of the recent papers that present possible advancements in the methodology will be cited here. The WJE configuration is wellsuited to theLCEC problem. Stojanovic et al. evaluated cylindrical wire, thin-layer, and WJEdetectors with constant and pulsed amperometric (PAD) modes of operation for the determination of inorganic arsenic (B151). In their hands, the WJE had the best LOD. Other recent examples of WJE LCEC detection can be mentioned (B152, B153). It can be noted, however, that the impressive sensitivity of carbon-fiber detectors, which has been exploited in the determination of catecholamines in single bovine adrenomedullary cells (B154),is difficult to match. Electrochemical detection has been applied to capillary electrophoresis with much success. Sloss and Ewing, for example, have improved their methods by enlarging the end of the capillary to accommodate a larger UME. Problems with variation of the capillary/electrode alignment were also minimized with their new design, which gave detection limits as low as 11 amol for catechol (B155).Lunte and co-workers have given details on the construction of a complete capillary electrophoresis system with electrochemical detection (B156). They found that a 50-pm-diameter Au(Hg) amalgam UME functioned well as a C E detector for free thiols (B157). Lu and Cassidy evaluated several UMEs in a WJE configuration as detectors for capillary electrophoresis columns. Not unexpectedly, mercury amalgam electrodes gave the best performance for 14 test metal ions (8158) and PAD at a Au UME worked well on the anodic side (B159). Mahoney et al. modified a commercial stationary mercury drop electrode apparatus so that square-wave voltammograms could be obtained under stopped-flow conditions (B160). Rapid-scan voltammetry at a UME detector was shown to give theoretical steady-state CVs under chromatographic conditions (B161). Trade-offs in sweep rate, UME diameter, and flow rate were evaluated. Two groups have put 16-element LCEC amperometric detectors to good use. In the study of Sparks and Geng, detection over a potential window of 0.75 V greatly increased the information content of a single chromatogram (B162).In the impressive work of Aoki et al., 80-channel detection was achieved by application of a five-step E-staircase waveform with 10-mV step heights to the 16 elements oft he array (8163). IDAs operated in the dual-electrode mode were shown to have good sensitivities as flow detectors: 100 pM dopamine was detected under HPLC conditions (B164). An advantage of this mode of detection is that the component of the current due to redox cycling is flow rate independent. Descriptions of several novel spectroelectrochemical flow detectors have appeared. Brown et al. used anodic photocurrents at Ti02 to detect species with redox potentials more negative than the valence band edge of the semiconductor at the 100-pmol concentration level (B165). Another flow cell was based on indirect detection of eluents by the decrease in the intensity of electrogenerated luminol chemiluminescence (B166). Also, a pulsed flash photolysis amperometric detector was described that appears to have some promise as a general purpose LCEC detector (B167). Several papers have proposed various surface modifications to improve LCEC response. The dual-electrode sensor of 368R
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Doherty et al., which is based on redox polymer-modified electrodes, nicely performs speciation analysis of Fe(I1) and Fe(II1) (B168). One electrode was coated with a Ru-bpy polymer (E1p = 0.75 V vs SCE), which mediated the oxidation of Fe(II), and the other was coated with an Os-bpy polymer (E1p = 0.25 Vvs SCE), which mediated the Fe(II1) reduction. The latter electrode was also used for the FIA of nitrite ion with excellent sensitivity and stability of response (B169). Wang et al. employed self-assembled monolayers (SAMs) of n-alkanethiols on Au electrodes to vary the response of LCEC detectors to analytes such as chlorpromazine in urine samples (BZ70). The SAM-modified electrodes discriminated against small ionic electroactive species and were stable under the hydrodynamic conditions of the flow cells. Mark and colleagues (B171), and others (B172), have found that conducting polymer film electrodes show improved performance in terms of sensitivity and antifouling properties for the detection of ionic species. Numerous examples of chromatographic analyses employing electrochemical detection can be found in the forests of chromatography literature. Examples of pulse amperometric detection include a study of the sulfur compounds cysteine, cystine, methionine, and glutathione, all of which were detected in human blood samples using simple LC PAD procedures (8173). PAD and HPLC/MS were employed in complementary fashion for the analysis of aminoglyoside antibiotics (B174); SO2 has been analyzed in beer by IC with PAD detection (B175);and HPLC of amino acids using PAD had excellent sensitivity and required little to no sample preparation (BI 7 6 ) . Johnson and co-workers have published two papers refining their PAD methodology. In one, pulsed voltammetry at a RDE was used to optimize the potential and time parameters for the PAD waveforms (B177), and the second gives construction details for a simple low-cost LCEC detector employing a gold working electrode (B178). Other examples of LCEC that caught your reviewer’s eye were a fast-scan voltammetric detection of fullerenes (BI 7 9 ) , detection of underivatized polypeptidesusing constant potential amperometry (B180), and the coulometric detection of neurotransmitters and respiratory metabolites in brain tissue (B181). Zhu and Curran considered porous flow-through amperometric detectors under conditions of low conversion efficiencies (B182). RVC electrodes were used to test the theory which predicted that the limiting currents were proportional to the 2 / 3 power of the pore diameter. A UME biamperometric GC detector was evaluated (B183).
C. ANALYTICAL VOLTAMMETRY Methodologies. The year 1992 marked the 40th anniversary of the publication of the seminal article by Barker and Jenkins on square-wave polarography. This paper was reprinted by the Analyst in honor of the event (C1), along with a retrospective by Barker and Gardner (C2). The development of square-wave voltammetry (SWV), as well as other electroanalytical techniques, has continued over the past two years. For example, Chin et al. ( C 3 ) reported on the mathematicalenhancement ofSWV. Lovricet al. (C4)treated theoretically the use of SWV in cathodic stripping, while Komorsky-Lovric et al. (C5)looked at peakcurrent/frequency
relationships in adsorptive stripping. The theory and experimental verification of pseudopolarography at the mercury hemisphere ultramicroelectrode was examined for use in anodic stripping voltammetry and metal speciation studies (C6).A reference element (internal standard) method was examined for the analysis of natural waters by stripping voltammetry (C7). As in the past review, adsorptive stripping voltammetry has been the most dominant approach that has been reported. Jin et al. (C8) studied the amount adsorbed in the adsorptive accumulation at a symmetric spherical electrode in a stirred solution. Li, James, and Magee(C9) examined the effect of the accumulation potential in the adsorptive stripping voltammetry of organochlorine compounds. As will be seen below, the analysis of metals by an adsorbed metal complex has been quite productive. The induced reactant adsorption in pulse polarography was examined by Puy et al. in a series ofarticles ( C I e C 1 2 ) . Jin et al. (C13)compared conventional and derivative measuring techniques for linear potential sweep adsorption stripping voltammetry. Stripping Voltammetry. The scope and selectivity of adsorptive stripping voltammetry has been greatly extended by the use of complexing agents either in solution or attached to the electrode. This has enabled adsorptive stripping voltammetry to beextended to a wide range of metals. Carbon paste electrodes are excellent candidates in that a wide variety of reagents can be incorporated into the paste. For example, the incorporation of salicylideneamino-2-thiophenolallowed for the accumulation and adsorptivestripping of copper (C14). A functionalized silica gel was incorporated into carbon paste for the adsorptive stripping of mercury(I1) (C15). Mercury (C16) and thallium (C17) were concentrated with anion exchangers which were present in the carbon paste. A diphenylcarbazide-modified carbon paste electrode was used for the determination of chromium(V1) and chromium(II1) (C18). Gold was selectively extracted with triisooctylaminemodified carbon paste (C19) or with thiobenzanilide (C20). A long alkyl chain amine was used for the selective determination of pyridoxal in nonfat dry milk (C21). A mossmodified carbon paste electrode was found to efficiently bioaccumulate lead (C22). Organic cations such as paraquat were determined by adsorptive stripping voltammetry with Amberlite resin in carbon paste electrodes (C23) or an ion pair at a hanging mercury drop electrode (C24). Silicamodified carbon paste electrodes were used for the determination of todralazine in biological fluids (C25). OV-17 silicone-modified carbon paste electrodes selectively concentrated organic compounds such as benomyl prior to analysis (C26). A diphenyl ether graphite paste electrode was used in the analysis of vanillin (C27). While carbon paste has been the most popular electrode material, other electrodes have been derivatized or modified in some manner so as to provide for preconcentration prior to the stripping analysis. Nafion mercury film-modified electrodes were used for the anodic stripping voltammetry of bismuth (C28). A glassy carbon electrode coated with a Nafion film was used to preconcentrate a nitrosoamine ((229). Gold(II1) was determined by anodic stripping voltammetry using a glassy carbon electrode with an aza crown ether (C30).
While significant sensitivity and selectivity enhancement can be obtained by covalently bonding or mechanically entrapping an agent near the electrode, similar results can be obtained by forming strongly adsorbable complexes in solution. Some examples are the use of Beryllon I11 to form complexes with beryllium (C31) or copper (C32) prior to adsorptive stripping analysis. The same technique was used to determine aluminum (C33)or uranium (C34)with cupferron. Vanadium (C35)was determined by cathodic stripping voltammetry after deposition as the Solochrome Violet R S complex, while this same ligand can be used to determine aluminum by adsorptive stripping voltammetry (C36). Cathodic stripping voltammetry was used to determine tripeptides by the formation of the copper complex at a mercury electrode (C37, C38). Fulvic acid enhanced the adsorption of the Mo(V1)-phenanthroline complex in cathodic stripping analysis (C39). A wide variety of organic compounds can be adsorbed on electrode surfaces and are ideal candidates for adsorptive stripping voltammetry. This is especially true of pharmaceutical compounds. Some examples of the drugs, electroanalytical techniques, and sample matrices that have been examined in the past two years are summarized below in order to give the reader a flavor for the scope of the technique. Villar et al. (C40) determined mitoxantrone using phaseselective ac adsorptive stripping voltammetry in a flow system. Phase-selective ac adsorptive stripping voltammetry was also used in the analysis of folic acid on a mercury thin-film electrode (C41)and aminopterin on a mercury thin-filmcarbon fiber microelectrode (C42). Mercury-coated carbon fiber microelectrodes were also used in the adsorptive stripping voltammetry of folic acid and mitoxantrone (C43). Flunitrazepam (a psychotropic drug) (C44) and lormetazepam (C11) were determined in urine by adsorptive stripping. Ranitidine in stomach tissue was determined by the same technique (C45),as was metronidazole in human serum (C46). Cholesterol (C47)in blood serum and testosterone propionate in pharmaceutical preparations (C48) was determined following adsorptive preconcentration. Multispecies analysis was obtained for the determination of riboflavin and folic acid in multivitamin preparations (C49) and nickel(I1) and cobalt(11) on a rotating disk mercury film electrode (C50). Economou and Fielden (C51),though, investigated the effect of surfactants on adsorptive stripping voltammetry and found that interferences can occur on the milligram per liter level. They examined the use of fumed silica gel and Nafion films to alleviate these problems. A more forceful way of applying the sample to the surface was utilized in abrasive stripping voltammetry, where the sample is physically deposited unto the surface. KomorskyLovric et al. compared the use of electrochemical and abrasive deposition onto a paraffin-impregnated graphite electrode for the analysis of lead and mercury (C52). Scholz et al. (C53) examined the anodic dissolution of dental amalgams by abrasive stripping voltammetry. This same stripping technique was also used to study the thermodynamics of solid-phase transitions (C54). There were several reports over the past two years on the use of new electrodes for anodic stripping voltammetry. Mercury films on conducting poly(3-methylthiophene) (C55) or poly-N-ethyltyramine (C56) on carbon surfaces were Analytical Chemistty, Voi. 66, No. 12, June 15, 1994
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reported. Wang et al. investigated the use of mercury-coated carbon foam composite electrodes (C57), vitreous carbon aerogel electrodes (C58), and screen-printed stripping electrodes (C59). Frenzel (C60) discussed the attributes and problems of using mercury films on a glassy carbon support. Ultramicroelectrodes have also been applied to anodic stripping analysis. A mercury ultramicroelectrode electrode was used by Peng and Jin (C61) to determine lead in a sample-limited analysis (e.g., 1 mg of hair). Gold fiber microelectrodes were used to determine mercury in high-purity gallium arsenide (C62)or waters and fertilizers (C63),mushrooms (C64),and selenium( IV) in blood serum (C65). Copper (C66)and lead/ cadmium (C67) were determined in the absence or presence of low concentrations of supporting electrolyte. Kouvanes and Deng (C68)examined the use of an iridium-based mercury ultramicroelectrode with square-wave anodic stripping voltammetry. The effectiveness of various methods to remove interferences in anodic stripping voltammetry was examined. The influence of complexing agents on the effectiveness of electrochemical masking with anionic surfactants was examined by Opydo (C69). The detection of Ga-Zn intermetallic compounds and its removal with antimony was reported by Cofre and Brinck (C70). Surfactants were used to suppress the indium peak in the determination of lead in samples that contained large concentrations of indium (C71). A photochemical process was reported by Barisci and Wallace (C72) for the removal of oxygen in flowing solutions. Photochemistry was also used in sample preparation of heavy metals in peat (C73),while a digestion method for soil samples was reported by Fernando and Plambeck (C74). Systematic errors due to adsorption of metal complexes onto cell components were investigated (C75). Sodium and other impurities in alkoxysilanes were determined by anodic stripping square-wave voltammetry (C76). Metals are generally the most likely candidates for determination by anodic stripping voltammetry, but there are several reports on the determination of organic compounds, either directly or indirectly. Cholesterol in blood serum was found to be amenable to anodic stripping voltammetry (C77), as were ionic alkyllead compounds in natural waters (C78). An indirect method for the analysis of NTA and EDTA in natural water by means of a bismuth complex was reported (C79)* The bulk of the reports on cathodic stripping voltammetry has involved the determination of halides and chalcogens. For example, total inorganic iodine in seawater (C80) or a variety of sulfur species such as thiols, sulfides, cysteine, and cystine (C81) were also determined. Wang and Lu (C82) reported on the ultratrace measurement of selenium in the presence of rhodium. A mercury-coated carbon-fiber electrode was used for the determination of selenium(1V) in blood serum (C83). Smyth et al. (C84) reported on the determination of organic and inorganic selenium compounds, while Kotoucek et al. (C85) determined arsenic. Organic compounds such as cytosine 3’-phosphate (C86), thiamine (C87), pentamidine isethionate (C88), and glutathione in natural waters (C89) were amenable to cathodic stripping voltammetry. The adsorption of “reduced COZ”on platinum was the basis of a new technique for the determination of carbon dioxide (C90). 370R
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Wang and Tian (C91) developed a mercury-free disposal lead sensor based on potentiometric stripping voltammetry using gold-coated screen-printed electrodes. Xie and Huber (C92)used constant-current enhanced potentiometric stripping voltammetry for the analysis of cadmium. Potentiometric stripping voltammetric techniques were also developed for the determination of cadmium and lead in whole blood (C93), copper and lead in tap water (C94), and manganese (C95). Komorsky-Lovric and Branica (C96)compared potentiometric stripping voltammetry and square-wave voltammetry with respect to the influence of Triton X- 100. Aldstadt and Dewald (C97) studied the effect of model organic compounds on potentiometric stripping voltammetry with a cellulose acetate membrane covered electrode. Catalytic Methods. The combination of preconcentration of the analyte in stripping analysis and enhancement of the signal by use of a catalytic reaction (dual amplification) provides for a very attractive approach to develop extremely sensitive electroanalytical methods. Some examples of this methodology have been recently reported. One elegant approach is to use a complexing agent that is, itself, an oxidizing or reducing agent in the stripping step. This technique was used in the analysis of chromium (C98),molybdenum (C99), and thorium (C100) using cupferron as the ligand for adsorptive stripping voltammetry as well as the catalytic oxidizer in the stripping step. In addition to cupferron, organic hydroxy acids (CIOI) and chlorate (mandelate as the ligand) (C102)were used to determine molybdenum. Iron in seawater was determined by cathodic stripping with 2-nitroso-2naphthol and the use of hydrogen peroxide as the oxidizing agent in the stripping step (C10.3). Bobrowski and Bond (C104) combined adsorptive stripping voltammetry of a cobalt complex with the catalytic effect of nitrite on the stripping wave to enhance the sensitivity of the cobalt analysis. The catalytic reaction, alone, without prior accumulation, was used by Hsieh and Ong to determine molybdenum by differential pulse polarography (C105), and by Jiang et al. (C106) to determine nitrite. Derivatization Methods. The efficient conversion of electroinactive compounds to eiectroactive materials or to change the redox potential of electroactive materials can be exploited to develop new electroanalytical methods. For example, reactive organic halides can be determined at low levels via in situ generation of S-alkylisothiouronium salts (C107) with differential pulse polarography. Similarly, ethanol (CI08),amines ( C I 0 9 ) ,and amino acids (CIIO)can be determined via in situ generation of dithiocarbamates. Oxalate can be determined by differential pulse polarography after derivatization with o-phenylenediamine (C11I ) . Sulfanilic acid was converted into an azo compound prior to differential pulse polarographic measurement (CI 12). Somer and Kocak developed a method for the differential pulse polarographic determination of sulfur dioxide using selenite (C113). The reaction of ammonia with formaldehyde was used as the basis for the analysis of ammonia in seawater (CI 1 4 ) . The formation of nickel complexes with ampicillin and amoxycillin led to a selective differential pulse polarographic method (CI15). Analytical Use of Micelles. Micellar and emulsified media provide an efficient method for solubilization and transport
of the analyte to the electrode surface. Emulsified media were used to determine pesticides by differential pulse polarography (CI 1 6 4 1 18). The combination of micellar media and a surfactant-modified carbon paste electrode was used for the adsorptive stripping analysis of piroxicam (C119). Zinc in lubricating oils was determined in emulsified media (C120). Pulse and Sweep Methods. While prior accumulation of analyte can greatly lower the limit of detection, such sensitivity is often not required, and an accurate, direct method is appropriate. In this section, recent applications of direct voltammetric analysis will be reviewed. A number of articles addressed themselves to the determination of acidity in a variety of matrices. For example, steady-state voltammetry of simple and polyelectrolyte strong acids, as well as weak acids, with and without supporting electrolyte was examined (C121, C122). Ultramicroelectrodes were used to determine the total acidity in wines (C123)and the "in situ" acid number of fluid lubricants (phosphate esters) (C124). An ultramicrodisk electrode was used for the solid-state electroanalysis of silicotungstic acid single crystals (C125). The determination of elemental sulfur and sulfide was obtained by the use of ac voltammetry (CZ 26). Many examples of the use of differential pulse voltammetry to measure a substrate or impurity were reported. For example, furaltadone (CI 27) in milk and urine was determined by differential pulse polarography. Trace levels of selenium in Chinese herbal drugs (CI28) and total pyrethroid residues in stored cereals (CI29) were determined by differential pulse polarography. Impurities in several pharmaceutical preparations were determined by differential pulse polarography (C130, C131). Pulse methods were also found to be useful in the analysis of solid materials such as the determination of iron in Y Ba2(Cul,Fex)30, superconducting compounds (CI 32) or the analysis of additives such as iron, sulfur, or chromium oxide in soda lime silica glass (C133). The oxygen-to-uranium ratio in uranium dioxide was determined by differential pulse polarography (CI 34). A lichen-modified carbon paste electrode was found to be useful for the analysis of lead, copper, and mercury (C135). Mathematical methods to enhance the signal and resolution have been applied to various pulse techniques. The Kalman filter approach was used for curve resolution and quantification of pyrazines by differential pulse polarography (C136). Reverse differential pulse voltammetry was used by Matysik et al. (C137) to improve the resolution between various catechols such as norepinephrine and 3,4-dihydroxyphenylacetic acid. Engblom et al. (C138) studied mechanically generated noise in static mercury drop electrodes. Metal/Ligand Complexation Studies. The complexing ability of natural waters can significantly affect the bioavailability of metals. Electrochemical methods are ideal to probe these effects and give them a significant advantage over atomic methods. The derivation and application of steady-state (C139) or normal pulse (C140) voltammetry for the determination of formation constants were examined. An anodic stripping voltammetry titration technique was developed for estimating the complexation capacity of natural waters (C141). Anion coordination chemistry was studied by the application of the molar ratio method to competitive cyclic voltammetry
(C142). Esteban and Diaz-Cruz (C143) reported on a general voltammetric method for studying metal complexation in macromolecular systems. Zelic and Branica (C144)examined the influence of anion-induced adsorption on the voltammetric determination of stability constants. Van den Berg and Donat (C145) found that there was a linear relationship between the detection windowsof the analytical techniques and the detected metal complexation. They investigated the effect of multiple ligands on speciation studies as well as the presence of slow metal/ligand dissociation kinetics. The effect of deposition potential on the voltammetric determination of complexing ligand concentrations in seawater was also examined (C146). Equilibria that involved metal-humate complexes, as models for natural water and seawater studies, were examined using anodic stripping voltammetry. A modified carbon paste electrode was reported for the study of the metal humic complexation reaction (C147). A procedure for metal speciation studies in the natural environment was reported which involved ultrafiltration of the sample and the study of the complexation dissociation kinetics using anodic stripping voltammetry and ion exchange (C148). This approach allowed the study of dissociation kinetics that could be varied between 2 ms to 8 days. The effect of competitive kinetics between a solution copper complex and an iminodiacetate group, which was incorporated into a carbon paste electrode, was the basis for a copper speciation analysis (C149). A solution ligand competition technique was proposed for the voltammetric measurement of the labile metal fraction (C150). The basis of this technique is that the natural copper complex dissociates too slowly for the copper to be deposited while the ethylenediamine complex is labile and can be detected by anodic stripping voltammetry. The effect of sodium dodecyl sulfate on the measurement of labile copper(I1) in the presence of humic acid was examined (CIS]). Chemometric Approaches. The chemometric approach to linear calibration was used by Allus and Brereton (C152) to determine thallium in cement dust and sediment samples using anodic stripping voltammetry. Ni et al. (C153) developed a method for the analysis of mixtures of pyrazines, which are flavor components of cocoa. The severe overlap of the peaks would preclude normal voltammetric analysis, but the use of chemometric methods with differential pulse voltammetry made it possible to carry out the analysis. An expert system for the determination of trace metals was reported by Esteban et al. (C154, C155). The expert system guided the user through appropriate methods, data analysis, and interference problems.
D. HETEROGENEOUS/HOMOGENEOUS KINETICS Electron-TransferTheories. The solution and molecular factors that affect the electron-transfer process is a question of fundamental importance in electrochemistry and continues to be the focus of considerable research. Fawcett and Opallo ( D J ) examined the question of why activation enthalpies for anions were larger than for cations. They proposed that the differences may be due to outer-sphere contributions to the Gibb's energy of activation. They also examined 18 heterogeneous redox reactions and found that the degree of dependence bfthe rate constant on the longitudinal relaxation time of the solvent decreases with the heterogeneous rate Analytical Chemistty, Vol. 66,No. 12,June 15, 1994
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constant ( 0 2 ) . The results were discussed in light of contemporary electron-transfer theory. Phelps et al. ( 0 3 ) studied solvent dynamical effects in electron transfer with a series of sesquibicyclic hydrazines as a probe of coupled vibrational activation. These systems provide an interesting opportunity to assess the manner and extent in which overdamped solvent relaxation may limit the electron-transfer dynamics. Fawcett and Fedurco ( 0 4 ) examined medium effects on the electroreduction of benzophenone in aprotic solvents. The solvation of the activated complex was based on three contiguous spheres corresponding to the two phenyl rings and the carbonyl group and was used to assess the outersphere contribution to the Gibb’s activation energy. It has been found that the heterogeneous electron-transfer rate constant decreased as the size of the tetraalkylammonium cation in the supporting electrolyte increased. But Fawcett et al. ( 0 5 )found that the activation enthalpy was independent of the cation size and that the slow electron transfer was due to an adsorbed layer of cations at the electrode surface. Pressure was used by Cruanes et al. ( 0 6 ) to study solute/ solvent interaction in electron-transfer processes. Increases in pressure (up to 10 kbar) led to shifts in the redox potentials which were attributed to the effect of the metal cluster’s electronic structure on the overall size of the complex and on its ability to interact with the solvent. Fawcett et al. ( 0 7 ) reported on the use of buckminsterfullerene as a model reactant for testing electron-transfer theories. McDermott et al. ( 0 8 ) examined electron-transfer kinetics of aquated iron, europium, and vanadium couples at carbon electrodes and found innersphere catalysis by surface oxides. Straus and Voth ( 0 9 ) presented a computer simulation study of free energy curves in heterogeneous electron transfer. Dissociative electron-transfer reactions were studied extensively by Saveant and co-workers. As with the simpler heterogeneous electron-transfer reactions reported above, the role of the solvent was an important focus of these studies. The role of the solvent was examined by an ab initio study of the carbon halogen bond reductive cleavage in methyl and perfluoromethyl halides (010). New tests of the electrontransfer theory were examined using data derived from outersphere electron-transfer data gathered in the same solvent ( 0 1 1 ) . They also reported examples of passage from a sequential to a concerted mechanism in the electrochemical reductive cleavage of arylmethyl halides ( 0 1 2). Jaworski et al. ( 0 1 3 ) used the Hammett reaction constant for the twoelectron irreversible reductive cleavage of substituted chlorobenzenes and bromobenzenes to show the role of solvent relaxation dynamics in irreversible electrode processes accompanied by bond cleavage. Concurrent metal-ligand bond dissociation was reported by Carlin et al. ( 0 1 4 ) to lead to asymmetric electrode kinetics. Heterogeneous Kinetics. Methods to measure faster electron-transfer rates continue to be pursued. Karpinski and Osteryoung ( 0 1 5 ) used pulse times of 5 ps in normal and reverse pulse voltammetry to measure the electron-transfer rates of ferrocene (1.2 cm/s) and anthracene (0.73 cm/s) at 5-pm platinum electrodes. Safford and Weaver ( 0 1 6 ) used lower temperatures to determine rate constants for rapid electrode reactions using microelectrode voltammetry. U1tramicroelectrodes allow the charging current to decay rapidly, 372R
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and as a result, the voltammograms could be obtained with little of the charging current present. Lavagnini et al. ( 0 1 7 ) developed the theory for the measurement of electron-transfer rates under mixed spherical/semiinfinite linear diffusion at microdisk electrodes. Birke and Huang ( 0 1 8 ) investigated steady-state voltammetry for quasi-reversible heterogeneous electron transfer on a mercury oblate spheroidal microelectrode. Mirkin and Bard ( 0 1 9 )presented a simpleanalysis of quasi-reversible steady-state voltammograms using the E1/4, E , / * ,and E314 potentials. Kim et al. ( 0 2 0 ) examined the use of derivatives to analyze voltammograms for reversible, quasireversible, and irreversible electrode processes. Munoz et al. ( 0 2 1 ) found that electron-transfer processes with very low transfer coefficients led to a splitting of the differential pulse polarographic wave, even though there was only a single electron transfer. Engstrom et al. ( 0 2 2 ) used scanning electrochemical microscopy to observe microscopically local electron-transfer kinetics. Cassidy et al. ( 0 2 3 )extended cyclic voltammetric theory to a quasi-reversible system with a Gaussian distribution of heterogeneous rate constants. Mirkin et al. ( 0 2 4 ) used scanning electrochemical microscopy to measure fast heterogeneous kinetics. The heterogeneous rate constant for ferrocene in acetonitrile, which was measured at steady state with solution resistance and charging current, was found to be 3.7 cm/s, 2-4 times the values determined by fast-scan cyclic voltammetry. Accurate measurement of peak potentials and currents in transient signals are usually imperative in order to obtain good kinetics information. Andrieux et al. ( 0 2 5 ) examined methods to improve the kinetically relevant data in cyclic voltammetry and showed that filtering caused significant increases in systematic error which negated any advantage in the reduction of random error. Smith and White ( 0 2 6 ) cautioned that the use of ultramicroelectrodes with dimensions less than 0.1 pm will lead to violation of electroneutrality due to the high electric fields, even in the presence of excess supporting electrolytes. This can result in significantly enhanced or depressed values of the heterogeneous rate constant. Two reports, which take different approaches to the removal of iR drop in cyclic voltammetry, have appeared. Eichhorn et al. ( 0 2 7 ) used a numerical method to correct iR drop errors for (quasi-)reversible electrode processes, while Hsueh and Brajter-Toth ( 0 2 8 ) used on-line iR compensation at carbon fiber ultramicroelectrodes. Homogeneous Kinetics. The development of much more efficient numerical methods for solving diffusion/kinetic problems has continued unabated. Most electrochemical mechanisms are a combination of several kinetic steps that must be considered if a complete fit of the data over a wide time window is to be attempted. This can only be accomplished by fast and accurate algorithms. Bieniasz (D29) proposed a dynamically adaptive grid technique for the solution of finite difference equations with a fast homogeneous reaction. While the approach is not entirely satisfactory at present, this strategy does permit the simulation of homogeneous rate constants that are as much as 20 orders of magnitude faster than the maximum possible in corresponding fixed-grid calculations with the same number of space grid points. Horno et al. ( 0 3 0 ) presented a network approach to the simulation of electrochemical processes where space was discretized but
time was continuous, This allowed a mathematical model to be described by a network model and its simulation could then be carried out by a suitable electric simulation routine without having to deal explicitly with thedifferential equations. Rudolph (031)reported an improved treatment of electrochemical mechanisms with second-order reactions using the fast implicit finite difference (FIFD) algorithm. Britz (032) incorporated the Crank-Nicolson scheme and N-point boundary expression into the Rudolph algorithm. Storzbach and Heinze (033)simulated electrode processes at macro- and microelectrodes using the Crank-Nicolson technique. The simulations included iR effects and double-layer capacitance as well as the heterogeneous/homogeneous reactions. Bieniasz and Britz (034) presented electrochemical simulations of mixed diffusion/ homogeneous reaction problems by the Saul’yev finite difference algorithm. They also compared the efficiency of electrochemical simulations by orthogonal collocation and finite difference methods (035). A very interesting and valuable report on the von Neumann stability of finite difference algorithm was published by Bieniasz (036). The stability of the explicit, second-order Runge-Kutta, DuFort-Frankel, fully implicit, Crank-Nicolson, and Saul’yev methods was examined. It was found that the stability depends notonlyon the DAt/h2(A) factor but alsoon therateconstant. In examining the error growth as time goes to infinity, the criterion of h < 0.5 is insufficient for stability when homogeneous reaction kinetics are involved. Mirkin and Bard (037, 038) used multidimensional integral equations to solve microelectrode diffusion problems with application to microband electrodes and scanning electrochemical microscopy. Second-order homogeneous chemical reactions were also studied by scanning electrochemical microscopy (039).Che and Dong published a series of papers on the theory for the use of ultramicroelectrodes to study first- and second-order homogeneous catalytic reactions (040-042). Lavagnini et al. (043)carried out the digital simulation of steady-state and non-steady-state voltammetric responses for electrochemical reactions occurring at an inlaid microdisk electrode. In this work, they examined the ECi, catalytic, and C E first-order reactions. Evans (044)examined the two-component diffusion (involving cyclodextrin equilibria) with reaction in chronoamperometry. Andrieux et al. (045) studied the response of an irreversible system to repetitive cyclic voltammetry. Maestre et al. (046)applied Matsuda’s pulse polarographic theory to the study of the C E mechanism by differential pulse polarography. Mellado et al. (047) derived the theory for electrochemical processes preceded by concurrent first-order chemical reactions in dc polarography. Laviron and Meunier-Prest (048)examined the cubic scheme with electrochemical reactions and protonations at equilibrium. Vincent and Peters (049)carried out the computer simulation of large-scale controlled-potential electrolysis involving father, son and grandfather, grandson self-protonation systems. Kumar and Birke (050)used global analysis of current/potential time data to study an EC reaction. Bieniasz presented a PC program, ELSIM, which can simulate a variety of electrochemical mechanisms by finite difference or orthogonal collocation methods (051). A very attractive approach for the construction of digital simulation programs was reported where the equations which describe
the electrochemical kinetic initial and boundary value problems are treated as text input data for a special formula translator (052). The use of a knowledge-based system for automatic polarographic elucidation of the ECE, EE, and adsorption mechanisms was reported by Palys et al. (053). Hydrodynamic methods are quite attractive for kinetics studies becauseone does not need to measure a transient signal. Compton et al. examined thin-layer effects and the shape of quasi-reversible current/voltage curve (054)and the catalytic mechanism (055,056) for channel electrode voltammetry. It was also found that radial diffusion must be considered at the wall jet electrode in order to have a full quantitative description of the steady state or transient current (057).The authors reported that this additional computational complexity may limit this technique for use in kinetic studies. Benderskii and Mairanovskii (058) described numerical/analytical methods to study ECE processes at the rotating disk electrode. Daasbjerg (059)reported on a new method for studying the competition between coupling or further reduction of electrogenerated material using a rotating disk or ultramicroelectrode. Double-Layer Studies. There was considerable interest in the electrical double layer that extended well beyond electroanalytical considerations. While beyond the scope of this review, there were many studies on electrical double layers at nonconducting surfaces, in colloids, and in chromatography. For electrochemists, an understanding of the electrical double layer is tightly connected to an understanding of the electrontransfer process, which occurs within that region. Murphy et al. (060)presented a numerical study of the equilibrium and nonequilibrium diffuse double layer applying the finite difference method to the Nernst-Planck and Poisson equations. Karasevskii et al. (061)developed a self-consistent theory of the metal/solvent boundary using a jellium model of the metal and a continuum solvent model. They found the existence of a quasi-metal layer in the near electrode region which provides a novel explanation of the large width (3-5 A) for the area of adiabatic reaction, the independence of the heterogeneous rate constant on the nature of the metal, and the capacitance properties of the boundary. Damaskin and Safonov (062) studied the mercury/water interface using a model which separates the diffusion layer region with a reduced value of the dielectric constant that is inaccessible for some electrolyte ions. Izotov and Kuznetsov (063)examined changes in the electron-transfer coefficient caused by the rearrangement of the compact double layer following changes in electrode potential. Hsu and Kuo (064)derived approximate analytical expressions for the properties of an electrical double layer with asymmetric electrolytes. Daghetti et al. (065)calculated single ion activities based on the electrical double-layer model. Hamelin et al. (066)tested the Gouy-Chapman theory at a (1 11) silver single crystal electrode. Fawcett et al. examined the double layer in ethanolic solutions (067)and applied the ac admittance technique to double-layer studies on polycrystalline gold electrodes (068). Wandlowski and DeLevie (069-071) studied the doublelayer dynamics in the adsorption of tetrabutylammonium ions at the mercury/water interface. Swietlow et al. (072)carried out double-layer capacitance measurements of self-assembled layers on gold electrodes. Studies on the structure of the Analytical Chemistry, Vol. 66,No. 12, June 15, 1994
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interphases of low melting point salts and protonic hydrates with mercury and gold ( 0 7 3 )and solvent effects in the doublelayer structure for gallium and gallium-like metals ( 0 7 4 )were examined. Perez et al. ( 0 7 5 ) studied the Hg/aqueous KCl interface from ambient temperature to 300 OC. Bai et al. ( 0 7 6 ) investigated the problem of real-area determinations of rough or porous, gas-evolving electrodes and the distinction between capacitance of the double layer and the pseudocapacitance due to adsorbed hydrogen. Jaworski and McCreery studied double-layer and ion adsorption effects in laserinduced transient currents on glassy carbon electrodes ( 0 7 7 ) . Leibig and Halsey ( 0 7 8 , 0 7 9 ) used double-layer impedance as a probe of surface roughness. Adsorption Studies. Because adsorption processes have a great impact on electron-transfer kinetics, double-layer structure, and electroanalytical techniques, efficient and reliable methods for studying adsorption have been pursued. Unwin and Bard ( 0 8 0 )used ultramicroelectrode voltammetry to measure adsorption isotherms in a drop of solution. These authors also used scanning electrochemical microscopeinduced desorption to measure adsorption/desorption kinetics and surface diffusion rates ( 0 8 1 ) . Three-dimensional phasesensitive ac voltammetry was used to study the adsorption of sodium dodecyl sulfate at the mercury/electrolytic solution interface ( 0 8 2 ) . Gu et al. ( 0 8 3 )used fast potential relaxation transients to distinguish between double-layer and adsorption capacitance. Blankenborg et al. ( 0 8 4 ) examined the reduction of Tl(1) at a mercury surfaceand found that, for weak linear adsorption processes, it was impossible to distinguish between the direct reduction of TI(]) and the formation of an adsorbed Tl(1) intermediate. Avaca et al. ( 0 8 5 )described the theory of cyclic voltammetry for quasi-reversible electrodeposition reactions with insoluble products. Tilak and Conway ( 0 8 6 )determined the analytical relationships between reaction order and Tafel slope derivatives for electrocatalytic reactions involving chemisorbed intermediates. Song et al. ( 0 8 7 ) developed the theory for quasi-reversible electron-transfer reactions with adsorption of the redox species using integer and half-integer integrals. Jin et al. ( 0 8 8 , 0 8 9 ) examined the theory for an irreversible interfacial reaction in linear potential sweep adsorption voltammetry. The characterization of a totally irreversible reduction of an adsorbate ( 0 9 0 ) and quasireversible surface processes ( 0 9 1 ) by square-wave voltammetry was reported. Rouquette Sanchez and Picard ( 0 9 2 ) developed the theoretical expressions for the steady-state current/potential curves for the electrochemical oxidation of a metal involving two successive charge-transfer steps with adsorbed intermediate species. The role of surface defects in the adsorption and electron-transfer kinetics of anthraquinonedisulfonate on ordered graphite electrodes was reported by McDermott et al. ( 0 9 3 ) . Engelman and Evans ( 0 9 4 ) used explicit finite-difference digital simulation of the effects of rate-controlled product adsorption or deposition in cyclic chronocoulometry. The simulation of Frumkin-type adsorption processes by orthogonal collocation using cyclic voltammetry was reported by Schulz and Speiser ( 0 9 5 ) . The experimental verification of theoretically predicted effects of reactant adsorption in normal pulse polarography was reported by Lukaszewski et al. ( 0 9 6 ) .The 374R
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semiintegral method was used to measure surface excess and weak adsorption ( 0 9 7 , 0 9 8 ) .
E. SURFACE ELECTROCHEMISTRY This section is organized by the nature of the working electrode. The major theme of the articles selected for mention here is characterization of the electrode surfaces and the reactions of adsorbed species. Theoretical Aspects. The articles cited in this section have a decidedly fundamental bent; it is noted, however, that important theory is often published in conjunction with experimental results, so this is not an exhaustive compilation. Leiva carried out a self-consistent calculation of the electron density that included pseudopotentials to estimate the contribution of the metal to the double-layer capacity at thin metal films of Pb and Ag ( E l ) . Trasatti has analyzed the variation of the work function for single crystal Au and Ag electrodes as a function of the Epzc( E 2 ) . Wandlowski and de Levie ( E 3 ) invoked a two-dimensional surface cluster model to explain the admittance of "needle peaks" that are seen in Cdl-E curves for the Hg/H20 interface in solutions of tetrabutylammonium salts. Their theory took into account growth and dissolution of the surface clusters both at the perimeter edge and at the cluster/electrolyte interface. A similar model was used by Schrettenbrunner et al. in their analysis of film formation at the Hg/CH$N interface ( E 4 ) . Nikitas also treated micelle formation on electrode surfaces ( E 5 ) . H e predicted a close correlation between aggregate formation from a dilute solution of monomers and surface phase transformations that would result in abrupt steps in the charge density and cdl vs E curves. In previous papers, de Levie and co-workers considered the effect of the time-dependent relaxation of the diffusion layer on the value of Cdl when speciesaredesorbed from an electrode surface ( E 6 ) . Using digital simulation and assuming a Frumkin isotherm, they explained the transients quantitatively. In the case of a linear isotherm, they derived an explicit relation for the time dependence of the interfacial excess for various adsorption/desorption rate constants ( E 7 ) . In several papers Nikitas has described surface phase transitions and adsorbate reorientations in statistical mechanical and thermodynamic rigor (E8-EI0). Among the conclusions of this work are that only irreversible phase transitionscan take place at constant chargedensity ( E 8 ) and that the diffuse layer capacity, and the capacity of the entire interface, cannot be negative if the electrical double layer is under potential control ( E l l ) . The use of the electrode potential as the independent variable is promoted and negative capacities are concluded to be a result of an incorrect choice of the independent variable. Increase in surface heterogeneity is predicted to disfavor surface phase transitions, an effect predicted on solid electrodes but not on mercury (E12). Nikitas has also presented a thermodynamic treatment of the monolayer formation of a salt film on an electrode surface (E13). Monte Carlo statistical mechanical simulations of the freeenergy profiles of sodium ions at a metal electrode have been made for water and T H F solutions ( E l 4 ) . In both solvents, a single, fairly deep minimum is found corresponding to the sodium ion with its first shell of solvent molecules in contact
with the electrode. Thus the O H P is predicted to reside about one solvent diameter closer to the electrode than in classical models, in which an adsorbed noncomplexed solvent layer is assumed to exist in the inner layer. A theoretical analysis of molecular polarization and interactions in adsorbed monolayers permited calculation of isotherms for adatoms and for competitive adsorption of ions and dipoles ( E I 5 ) . Several papers have concerned the ac impedance of surface reactions (El6-E18). These include an analysis of the impedance of an (Ox/R),ds couple for both planar and porous surfaces ( E l 6 ) and for the situation where two different adsorbed intermediates are involved in the electrode reaction (El7). Scott has presented electrochemical rate equations for several reaction mechanisms involvingadsorbed intermediates (E19). Rather than power law expressions, the rate is expressed in a “Langmuir” isotherm model in which the influence of electrode potential and concentration can be assessed separately. On a similar theme, Tilak and Conway derived relationships between reaction orders and Tafel slopes for electrocatalytic reactions involvingadsorbed intermediates (E20). Various adsorption isotherms were factored into their theory, which was applied to several experimental situations including the anodic Cl2 evolution process. Following up on previous work, Mishra et al. predicted maxima in i-E curves for chemisorbed states (E2I). Also expressions for i-E curves have been derived for a two-electron reaction mechanism with an adsorbed intermediate (E22). Several worthwhile papers have appeared on the squarewave voltammetry of surface reactions. SWV was used to characterize quasi-reversible surface waves using the COOL nonlinear least-squares algorithm for data analysis. Various SWV peak shapes were observed, theoretically and experimentally for the azobenzene system, that were dependent on the rate constant, the S W amplitude, and the pulse width (E23). O D e a et al. have also given SWV theory for a totally irreversible electrolysis of an adsorbed species. Experimental voltammograms were compared directly in real time with a numerical solution of the boundary value problem using the COOL algorithm to yield estimates of the transfer coefficient and the rate constant (E24). An easily implemented theory for quasi-reversible cyclic SWV for a surface-confined redox couple was given by Reeves et al. (E25). Their model assumed that lateral interactions among adsorbed species were negligible, that all surface sites were equivalent, and that there was no diffusional component of the current from solution species. Rate constants were extracted from the peak separations in the classical manner of cyclic voltammetry. Stripping SWV theory was developed for monomolecular layers of reversible, quasi-reversible, and irreversible M/Mn+ couples in a quite general fashion (E26). In other articles, stripping voltammograms of simple ionic salts were analyzed in terms of theory that embraced two activity models for the interfacial species (E27); reversible and quasi-reversible stripping of insoluble Hg salts accumulated at Hg drop electrodes was treated (E28);semiintegral voltammetry was applied to situations where weak adsorption exists and both surface and diffusional waves are observed (E29);and surface coverages were measured using a combination of chrono-
coulometry and semiintegral voltammetry for situations where both surface and diffusion components contributed to the current (E30). In a paper that illustrates well the difficulty of data interpretation, Kano and Uno have analyzed the quasireversible surface wave of several quinone couples in terms of two mechanisms: (i) a one-step, two-electron process; (b) a two-step E E process. In both cases Frumkin-type interactions between adsorbed molecules were taken into account and a Laviron approach was followed. They found somewhat better agreement with theory for the two-step EE mechanism (E31). Simulation of reversible CVs where both Ox and R obey Frumkin-type adsorption isotherms using an orthogonal collocation method demonstrated the effects of interaction parameters (E32). The general CV behavior was that of the classical Wopschall and Shain article. An earlier paper from the same group concerned the effect of coadsorption of an electroinactive product of a follow-up reaction (E33). Jin and co-workers have also presented theory for quasi-reversible surface waves in a manner similar to that of Laviron with slight modifications (E34-E36). Their treatments apply to various transformation voltammetries. Engelman and Evans simulated the chronocoulometric response for the situation of simultaneous adsorption and desorption of the product of an electrode reaction (E37). Input parameters for their program included rate constants for both the deposition/dissolution and the adsorption/desorption processes. Chronopotentiometric theory was presented for the process, aA n e- = bBads,assuming various electrode geometries and current/time excitation functions (E38). Recent treatments of the metal dissolution problem include an analysis of the steady-state i-E curves for an EEmechanism, assuming Butler-Volmer kinetics and potential independent constants for irreversible desorption steps (E39), and a calculation of the current distribution in a corroding pit using conformal mapping techniques (E40). Several papers havedealt with the effects of rough or fractal surfaces on double-layer impedance, mass transport, current density, etc. ( E 4 1 4 4 4 ) . Mercury Electrodes. A study of the adsorption of iodide at the H g / l M NaClO interface between 30 and 453 K is notable for the wide temperature range studied (E45). Partial charge transfer was invoked to explain the data. Isotherm parameters for the adsorption of iodide on H g from ethanol were compared to values in eight other solvents (E46). Specific adsorption of halide ions at the Hg/CH&N interface was studied using classical techniques (E47), and differential capacity measurements on the electrosorption of benzoic acid at the Hg/H20 interface indicated a “gas-to-solid” phase transformation that was driven by attractive dispersion forces (E48). Volume 349 of the Journal of Electroanalytical Chemistry, which consists of papers dedicated to Professor Lucien Gierst, contains several accounts of the formation of condensed films at mercury electrodes (E49-E53). Capacitive pits and condensed layer formation was described for thiouracil from CH3CN ( E M ) ,methylisoquinoline (E55),and N B q + on Hg ( E M ) . The adsorption of 28 heterocycles and naphthalenes on H g was analyzed in terms of an “intrinsic” Gibbs adsorption energy and a partial charge-transfer coefficient (E57).
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Several research groups have focused their attention on reorientation phenomena. Adsorbates studied include methylpyridines (E58),4-phenylpyridine (E59),uracil (E60), and nicotinic acid ( E 6 I ) . The article of Werner et al. on the adsorption of aniline is noteworthy due to the simultaneous differential capacity and spectroelectrochemical measurements of the Hg interface using second harmonic generation techniques ( E 6 2 ) . At negative potentials, where the aniline molecules are oriented perpendicular to the electrode surface, the SHG signal was only dependent on the metal electrode. Other studies include the report that the self-assembled monolayer of a C16 alkanethiol insulated Hg by a 1-V range ( E 6 3 ) and accounts of the adsorption of the zwitterion methionine (E64)and the highly symmetrical pentaerythritol molecule at the Hg/NaF(,,, interface (E65). The adsorption of a 1,4-benzodiazepine on Hg was measured in a chronocoulometric study (E66) and CVs of benzo[c]cinnoline were interpreted by assuming Langmuir isotherms and diffusional mass transport of one of the redox partners from the bulk of the solution (E67). Capacitance/time transients at the Hg/H20 interface have been analyzed in detail for the adsorption of Bu4N+ ions (E68), 5-methyluracil (E69),and 2-thiouracil ( E 7 0 ) . In the Bu4N+ system, the pit nucleation and growth was independent of the nature of the anion at low concentrations, but became anion dependent at higher concentrations. Papadopoulos et al. used phase-sensitive ac voltammetry to construct c d l vs E curves for different times during the adsorption of sodium dodecyl sulfate at Hg (E71),and Tomaic et al. obtained the volume of surface-active condensates such as methyl oleate and squalene from analysis of current/time transients at the DME in seawater solution ( E 7 2 ) . CVs of the Hg(cyclam)2+/Hg couple at Hg were complicated by base hydrolysis of the free ligand and the appearance of the Hg(OH)z/Hg wave ( E 7 3 ) . In a similar study, adsorption of Ni(cyclam)2+l+was found at Hg where the Ni(I)ads complex was involved in the electrocatalysis of C02 reduction ( E 7 4 ) . Solvent effects on the kinetics of a (NH3)&o(III/II) coupleadsorbed on Hg via a bridging ligand were correlated with longitudinal relaxation times for Debye solvents ( E 7 5 ) . A Fourier transform method was used to aid in the resolution of the diffusion peak and the postpeak that were seen in the differential pulse polarograms of the Pb2+/Pb(Hg) system in chloride media where there is weak adsorption of reactant (E76). Markedly different inhibitory behaviors were observed in the polarography of Cd2+ and Cr042- at n-hexyldecyltributylphosphonium-coatedelectrodes ( E 7 7 ) . The anodic formation of HgS films was reported to proceed via successive deposition of 2-D monolayers and 3-D islands (E78). Mattsson et al. studied the electrocrystallization and stripping of HgSe films which had been formed by the reduction of Se(1V) or by the oxidation of H2Se (E79). In the presence of selenate, the anodic polarographic current was reported to be controlled by the precipitation of Hg2SeO4 (E80). In the miscellaneous class, Kruijt et al. used a light scattering method to study the diffusion-controlled growth of an assembly of Hg spheres on a Pt surface held at constant potential ( E 8 I ) . 316U
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Carbon Electrodes. Considerable progress has made in the last two years in understanding the fundamental surface electrochemistry of carbon electrodes. Notable among the contributions are those of McCreery and his students, who have continued their penetrating research using surface Raman spectroscopy, a variety of nonfaradaic electrochemical measurements, electron-transfer rates of the Fe(CN),j3-I4- and related couples, surface imaging methods, and other methods to characterize HOPG and glassy carbon (GC) electrodes. In addition, the advent of surface microscopies into various electrochemistry laboratories has provided remarkable atomic level insight into what is going on at the carbon/solution interface during electrolysis. Kneten and McCreery reported that the electron-transfer (ET) rates of 13 redox couples were 1-5 orders of magnitude slower on basal plane HOPG than on laser-activated GC. Possible reasons advanced for the low rates on HOPG were the low density of electronic states in this material, the hydrophobicity of the surface, and the role of the GC surface in promoting H + transfer-coupled multistep processes (E82). The role of defect density on the basal plane of HOPG has been highlighted in several publications from McCreery's laboratory. For the anthraquinonedisulfonate system the values of ko,Cdl, and the surface coverage (I'T) were dependent on the defect density for HOPG (E83). Highly irreversible CVs were seen for the Fe(CN)63-/4- couple on defect-free surfaces. Intercalation of HOPG in aqueous acid solutions was studied by in situ Raman spectroscopy (E84). In 1 M H3P04, neither intercalation or lattice damage was observed at potentials up to 2.0 V vs SSCE, while in 1 M H2S04, HNO3, or HC104, intercalation always preceded or accompanied lattice damage. Slow ET was seen at fractured GC or HOPG electrodes for the aqueous Fe3+I2+, Eu3+I2+, and V3+12+ couples, consistent with their low homogeneous self-exchange rates ( E 8 5 ) . However, even slight oxidation of the carbon surface gave large increases in the observed rates, suggesting oxide mediated inner-sphere catalysis via intermediate surface complexes. SERS of GC and HOPG electrodes after deposition of 0.2 pmol/cm2 metallic silver permitted the formation of graphitic oxide to be distinguished (E86). For unadorned surfaces, the electrochemically formed graphite oxide layers were indistinguishable in the SERS spectra. Electroreflectance spectra of methylene blue on HOPG gave evidence of three different adsorption states, two of which on the basal plane were separated by ca. 0.1 V (E87). Goss et al. reported the first in situ imaging of blister formation and collapse at HOPG electrodes under oxidative cycling in HNO3(,,, (E88). They proposed a detailed mechanism for the submonolayer oxidation that involved electrolyticgas evolution at subsurface active sites. The blisters were 20-1000 nm in height and 0.5-50 pm at the base. Other in situ STM and AFM imaging of carbon electrodes included the study of Hendricks et al. on lead deposition on HOPG that was previously decorated with monolayer deep pits. Lead deposition and stripping at the rims of the pits can be seen in the published images (E89). Bard's group also achieved monolayer etching of the basal plane of HOPG using a STM tip under positive bias (E90). Lines and widths as small as
10 nm and squares 25 X 25 nm were formed. Others have used STM to follow the nucleation and 3-D growth of Pt deposition at HOPG surface defects (E91),the formation of condensed layers of adenine (E92), and the deposition of oxometalates (E93). Glassy carbon surfaces have been most intensely studied, no doubt due to their favorable characteristics as working electrodes. An important account of the modification of glassy carbon electrodes (E94) also gives a very thorough review of GC as a solid electrode material. The McCreery in situ laser activation technique for G C surfaces at power densities below 30 mW/cmz produced only slight changes in the SERS spectra, the l?T value for phenanthrenequinone, Cdl, and the SEM appearance of the polished surfaces (E95). However at fractured GC, or at fractured G C activated with three 70 mW/cmz laser pulses, a ko of 0.4 cm/s was measured for the Fe(CN)63-/k couple in 1 M KC1. STM images of G C surfaces that had been subjected to several pretreatment procedures showed varying degrees of roughness (E96). However, ET rates as measured by the ko for Fe(CN)63-Ik did not correlate with the surface roughness. This observation was said to be consistent with the previously widely held view that electrode activity is determined, to a large extent, as a result of active site exposure by means of whatever activation method is employed. Transient currents, which had components on the millisecond time scale, were produced at GC electrodes by intense laser pulses (9 ns at 1064 nm). They were attributed to perturbation and restoration of the diffuse double layer and adsorbed ions (E97). Zhang and Coury have made the useful observation that sonication of GC electrodes in dioxane leads to increased ET rates for aqueous redox couples (E98). Electrodes treated in this manner are more prone to adsorb redox-active compounds than more conventionally treated electrodes and remain active in aqueous solutions for days. Firouzi et al. imaged G C surfaces using phase detection interferometric microscopy. In NaOH(,,), application of 1.5-2.0 V vs SCE for several seconds generated mesas with heights up to 250 nm and diameters on the order of 30-70 pm (E99). An in situ ellipsometric study of the electrochemical activation of G C indicated formation of a highly porous, hydrated surface layer, which increased monotonically with activation time (E100). G C electrodes activated in air at 400-800 OC or in steam at 790-980 OC gave CVs that exhibited a quinone/hydroquinonelike couple (EJOI). An extensive account has appeared concerning the modification of GC, both surface and homogeneous modification, by low-temperature thermolysis of poly(pheny1enediacetylene) precursors (E94). Homogeneous incorporation of Pt, for example, into GC produced solid electrodes with electrocatalytic response for the reduction of 0 2 and H+.These novel materials were prepared by thermolysis of either mixtures of platinum oxide microcrystallites in a carrier polymeric precursor to GC or an organometallic polymer containing covalent Pt(0). TEM of the electrodes indicated a narrow size distribution of Pt clusters in the doped GC, with an average diameter of ca. 1.6 nm (E102). Chlorine- and fluorine-doped GC was synthesized by this method using perhalogenated oligomeric materials ( E l 0 3 ) . Electrodes of these materials
exhibited reasonably fast kinetics for the Fe(CN)&" couple, and interestingly, the fluoro-GC had very low double-layer capacities, on the order of 8 pF/cmZ. Several more conventional modifications of GC surfaces have been pursued in the past two years. Tateishi et al. found that ultrafine gold particles, 1-12 nm in diameter deposited on GC, produced an active surface for the oxidation of ethanol and acetaldehyde in alkaline solution ( ~ 0 4 )Similarly, . silvermodified GC was an efficient substrate for the oxidation of small organics (E105), and G C electrodes modified with the NiO/NiOOH couple worked well for the amperometric detection of aliphatic alcohols (E106). Kulesza et al. reported that the use of a Pt counter electrode in acidic media can lead to electrodeposition of Pt particles with diameters of 20-40 nm on graphite cathodes (E107). The electrocatalytic oxidation of As(II1) was used as a sensitive indicator for the presence of the Pt particles. Several Russian groups have reported the modification of G C with fluorosulfonic groups (E108,E109) or with CF, groups (E110).Prewaves in the CVs of aromatic carbonyl compounds at GC electrodes were attributed to acidic surface functionalities interacting with the C=O group of the carbonyl compound (E111,E112). GC electrode surfaces have been modified with covalently attached groups by the reduction of aromatic diazonium salts (E113, E l 14). For example, attachment of phenyl groups at coverages corresponding to a close-packed monolayer was demonstrated. The surfaces, which could be modified further by chemical reactions, were stable to ultrasonic cleaning and persistent over months. Several interesting surface electrochemical investigations have been carried out on carbon fiber electrodes in conjunction with their use as UMEs. Pantano and Kuhr performed sophisticated imaging of 10-pm fiber UMEs by two methods: (i) fluorescence from fluorophores attached to surfacecarboxyl groups via a linker arm containing a biotin-avidin complex and (ii) luminol ECL generated at ET sites on the surface. Surface heterogeneity was evident at the submicrometer level in the polished and electrochemically treated surfaces (E1 15). Kawagoe et al., who analyzed the pH dependence of both quinone reduction and dopamine oxidation at carbon fiber electrodes, concluded that there were mechanistic differences between the reactions on carbon fiber and on conventional electrodes (E116). Several papers have described the effects of electrochemical pretreatments of carbon fiber electrodes (E1 17, E l 18). Swain and Kuwana found that Dupont pitch-based carbon fibers, which had been subjected to a sequence of high-current anodizations, underwent a surface-reforming process when followed by a vacuum heat treatment (E119). The ionexchange properties of oxidized carbon fiber bundles have been exploited in two studies of Jannakondakis and co-workers (E120,E121). Theionexchangecapacityofthefiberbundles was estimated at ca. 1 mequiv/g. Carbon fiber UMEs with cation selectivity were prepared by electropolymerization of phenolic compounds bearing ion-exchanging carboxylic or sulfonic groups (E122). Anodic oxidation of pyrolytic graphite in alkaline solution did not destroy the surface structure while introducing hydroxyl groups (E123). In acid, oxidation occurred to depths as great as 40 nm from the edge surface. Analflical Chemistry, Vol. 66, No. 12, June 15, 1994
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Several articles with innovative aspects have appeared describing carbon-based working electrodes. DNA-modified glassy carbon, immobilized via covalent bonds between deoxyguanosine residues and surface carboxylate groups, functioned as an electrochemical probe for the complementary oligonucleotide strand (E124). The electrochemical signal was that of C0(phen)3~+/~+ preconcentrated by the doublestrand hybrid structure. McFadden et al. prepared carbon electrodes by pyrolysis of natural gas onto Macor, a machinable ceramic substrate (E125). ET rates on these surfaces for the Fe(CN)63-/4- couple were comparable to those obtained on conventionally polished GC. A highly active electrocatalytic porous carbon surface for 0 2 reduction was prepared by adsorbing anionic Co complexes into oxidized poly(pyrro1e) followed by heat treatment at 820 "C under nitrogen (E126). A TEMPO-modified graphite felt electrode was used for the efficient electrocatalytic coupling of methylquinolines ( E l 27). Wang et al. (E128) evaluated epoxy-composite pellets as voltammetric working electrodes that were fabricated from carbon aerogel foams with high surface area and ultrafine pore sizes (C50 nm). Two groups have used boron-doped diamond films as working electrodes (E129, E130). The reduction of nitrate to ammonia in alkaline solution proceeded withgood Coulombicefficiencyat oneofthesesurfaces (E130). Screen-printed carbon electrodes have been promoted as amperometric sensor electrodes (E131, E132). Conducting salt/silicone oil paste electrodes (E133) and metal-dispersed carbon paste electrodes (E134) were found to be electrocatalytically active. Studies on adsorbed molecules on graphite electrodes are cited here and in the vast section F below on modified electrodes. The properties of ruthenium(II1) oxide and cyanide films on carbon substrates for electrocatalytic oxygen atom transfer reactions has been examined. Mixed-valent Ru( II1,IV)-oxo centers were found to show specific reactivity toward As(II1) and CH30H oxidation (E135). Pyrolyzed Fe and Co tetraphenylporphyrins and Fe- and Co-crowned phthalocyanines were evaluated with respect to electrocatalysis of the 0 2 reduction (E136, E137); covalently attached Co'Itetraphenylporphyrin on glassy carbon effectively electrocatalyzed the reduction of C02 to C O (E138);an adsorbed Cu-phenanthroline complex on graphite electrocatalyzed the reduction of 0 2 and H202 via an EE mechanism (E139E1 41); an adsorbed electroactive alizarin quinone, with the ability to complex Fe(III/II) couples, mediated the reduction of 0 2 and H202 at graphite electrodes (E142);and chloro(phtha1ocyanine)rhodium complexes on HOPG underwent a slow solid-state electrodimerization that was coupled to the surface redox chemistry ( E 1 4 3 ) . Finally, in several studies Bond and co-workers have obtained meaningful voltammetry of water-insoluble compounds by mechanically transferring them to solid graphite electrode surfaces where surface redox reactions could be carried out in aqueous electrolyte solutions ( E 1 4 4 , E145).
Single Crystal Surfaces. On the basis of the number of papers and their volume, surface electrochemists have been busy researching a variety of well-defined single crystal electrodes in the last two years. Interlaced with diligent effort at characterization of the interfacial structures and mechanistic phenomena are two major themes: documentation of the role 378R
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of surface crystal structure on interfacial phenomena and the study of surface reconstruction reactions. It is now clear from numerous examples that surface structure can have remarkable effects on the mechanisms of a wide variety of electrode reactions. In many cases this has provided great detail on the nature of intermediates and key steps in these processes. In addition, in the past year or so there have appeared several really elegant applications of the new surface microscopies, e.g., STM and AFM, to the study of phenomena at single crystal interfaces. Platinum(n,n,n). Examples of surface structure-sensitive reactions are the oxidation of small organic molecules such as glucose (E146), squaric acid (E147), and ethylene glycol (E148)at Pt single crystal electrodes in aqueous acid solution. In the work of Llorca et al. (E146), voltammetric currents were correlated with edge site processes. Different crystal faces of a working electrode will display widely different activities under identical conditions. For example, Pt( 1 10) was found to be most active for the oxidation of squaric acid (E147) and ethylene glycol (E148), while P t ( l l 1 ) was the most active for the electrooxidation of glycerol in alkaline solution (E149). For the oxidation of glucose, Tafel slopes of 120 and 60 mV were obtained on Pt( 11 1) and Pt(100), respectively, along with different adsorbed intermediates, gluconolactone on Pt( 11 1) and CO on Pt( 100) (E150). On the other hand, the oxidation of glyoxylic acid in H2S04(aq) was reported to be mostly insensitive to the structure of Pt single crystal electrodes (E151). On the cathodic side, in situ electrochemical mass spectroscopy (EC-MS) clearly showed that only the Pt(100) face was active for the complete hydrogenation of benzene to C6H12 (E152). Benzene was desorbed from the (111) face and partially desorbed from the (100) face. Another EC-MS study also revealed significant differences in the operative mechanisms for the oxidation of ethylene on Pt( 11 1 ) and P t ( l l 0 ) surfaces (E153). Interestingly, oscillatory phenomena have been reported to be structure sensitive. Potential oscillations were seen during the oxidation of formic acid on Pt(100), but not on P t ( l l 1 ) (E15 4 , and during the electrocatalytic oxidation of H2 in the presence of Cu(I1) and C1- at Pt( 11 1) and Pt( loo), but not at Pt( 110) (E155). For inorganic systems, well-defined voltammograms for H N 0 2 / N O were obtained at Pt( 11 l ) , but not at Pt( 100) or P t ( l l 0 ) surfaces (E156). Rodes et al. (E157), however, reported irreversible oxidative adsorption of N O in a CV study of the reduction of nitrite at Pt( loo), and reduction of N02and NO to NH3 proceeded with an efficiency of >80% at Pt( 100) surfaces (E158). For hydrazine oxidation in acid, stable irreversibly adsorbed species were found at Pt( 1 lo), while reversible adsorption, without charge transfer, occurred on Pt(100) and P t ( l l 1 ) (E159). Nishihara et al. found competitive adsorption with H+ on both terrace and step sites for the oxidation of hydrazine at Pt(332) and P t ( l l 1 ) in H2SO4,aq) ( E I 6 0 ) . The adsorption of HS04- (E161, ,5162) and phosphate ions (E163)on Pt was sensitive to the surface geometries. The hydrogen region electrode process in NaOH(,,) was found to be strongly dependent on the exposed crystal planes at Pt low-index and stepped surfaces ( E l 6 4 ) . Adsorbed Pd atoms
on Pt( loo), -( 11l), and -( 110) exhibited different hydrogen adsorption behavior (EZ65), and the growth of Pt oxide films wasfasteronPt(ll0) thanon-(loo),-(11 1)orpolycrystalline surfaces (EZ66). Even the electropolymerization of 3-methylthiophene was dependent on the crystal structure of the Pt anode (EZ67). Likewise, the optical properties of Prussian-blue films, electrochemically grown on Pt( 11 1) and Au( 11 1) substrates, were similar to those on glassy carbon, while on Pt( 110) little film formation was seen (E168). Surface reconstruction phenomena have been found to be structure sensitive as well. Rodes and Clavilier, for example, found that, for stepped-terracePt surfaces, the reconstruction phenomena, which could be rationalized in part by a hardsphere model of the surface, were distinctly dependent on the width of the terraces (EZ69). Restructuring was indicated for Pt( 110) undergoing the hydrogen adsorption process in carbonate and bicarbonate solutions (E170) and for Pt( loo), -( 1 lo), and -( 11 1) surfaces in neutral phosphate buffers (E17Z). However, specific adsorption of anions on Pt( 100) in acid did not induce irreversible surface reconstruction (E172). Sumino and Shibata have reported the surface transformations of electrodeposited films of Pt on polycrystalline substrates, which can have (100) or (110) orientation, depending on the experimental conditions (EZ73, E174). Clavilier and Rodes investigated the effect of the quenching temperature on the CV response of Pt (33 1) ,- (553), and - (443) surfaces (EZ75). Two major groups have addressed difficulties in the evaluation of absolute surface coverage of adsorbed CO on single crystal electrodes (E176, E177). Related to this is the difficulty of determining the Epzcfor single crystal electrodes when reconstruction occurs (EZ78). Orts et al. reported that higher C O coverages were reached in solution than in the gas phase for Pt( 1 1 1) in H2S04(aq)(El77). Oxidation of CO and CO adlayer formation continue to be popular subjects for study at single crystal electrodes (El79-EZ81). Minimal toad, poisoning was reported for the oxidative dissociation of methanol at Pt(100) in Na2C03(,,) (E182) and for the oxidation of glycolic acid at Pt( 11 1) and Pt( 110) surfaces (E183). Detailed mechanistic studies on the important methanol oxidation process included a study in CD30H and CH3OH at Pt single crystal surfaces which reached the conclusion that a C-H bond was broken in the initial step (EZ84). This is in contrast to the UHV decomposition where 0-H undergoes initial scission at Pt. The orientations of nitrogen heterocycles such as substituted pyridines at P t ( l l 1 ) surfaces have been deduced by a combination of surface spectroscopies and electrochemistry (EZ85,EZ86). In several instances, surface layers, which were stable under vacuum, displayed the same electrochemical behavior before and after evacuation. Gomez and Clavilier studied Pt(l10) with a view to the role of surface domains and their size on the hydrogen desorption process (E187).Mixed adlatticesofC0 and iodine produced immiscible domains on Pt( 111) surfaces (E188). Optical second harmonic generation methods applied to the
Pt( 111)-iodine surface revealed symmetry changes of the monolayer structure (EZ89). The electrocatalytic role of bismuth adatoms has been addressed by several authors. Chang et al. attributed the 30-40-fold enhancement of formic acid oxidation rates at Pt(100) in HC104totheattenuationofCOad,coverage(EZ90). Formic acid oxidation was also catalyzed on Pt( 11l), although the major poison was not toads. In contrast, in the presence of predosed Bi, methanol oxidation was diminished on both Pt( 111) and -( 100). Campbell and Parsons also found that the oxidation of methanol was inhibited by submonolayer and monolayer coverages of both Sn and Bi on single crystal, polycrystalline, and dispersed Pt electrodes and that Bi submonolayers on Pt( 11 1) enhanced the oxidation of formic acid (E191). Weaver’s group has also studied the influence of Bi adatoms on the oxidation of ethylene glycol at Pt( 111) (EZ92). The redox behavior of Bi on Pt( 111) indicated that the adatom sites were dependent on the extent of surface coverage (E193). Copper deposition onto Pt single crystal electrodes has been the topic of several detailed studies. Reports have noted the dramatic effect of adsorbates on the UPD of Cu on Pt(n,n,n) electrodes. Adsorbates studied include anions such as C1and H S 0 4 - (EZ94, EZ95) and organic molecules such as hydroquinone (EZ96, E197). Cu, Pb and C O adsorbates on Pt( 11 1) in acid inhibited hydrogen adsorption and decreased the voltammetric peak presumably due to HSO4- adsorption (EZ98). Cadmium submonolayers also effect the adsorption of HSO4- on Pt( 111) (E199). Along this line, Varga et al. reported that Cu deposition on Pt( 111) produced active and inactive adlayers toward bisulfate adsorption (E200). In one of the more detailed studies, Michaelis and Kolb correlated the voltammetric waves in HzS04(aq) with copper deposition initially into every other trough in the Pt( 1 lo)-( 1 X 1) surface, followed by complete monolayer coverage in every trough in the second process (E201). In situ STM of Cu UPD on Pt(ll1) had previously indicated a two-step process (E202). Leung et al. explained apparent discrepancies between stripping coulometric charge and theory for complete monolayer coverage of Cu on Pt( 1 11) surfaces by partial charge transfer to the substrate (E203, E204). In the UPD of silver on iodine-covered Pt( 11 l), the Ag deposited underneath the iodine layer to form a Pt( 11 1)AgI surface (E205). At a thickness of two monolayers, the adsorption behavior of bisulfate on Ag deposited on Pt( 111) was similar to that on bulk silver (E206). Other studies include the concentration dependence of the UPD of Ag on Pt( 11 1) (E207), the epitaxial growth of Pd and Rh monolayers on Pt(l1 l)andPt(100) (E208),andtheadsorptionofGeadatoms on Pt single crystal electrodes (E209). Gold(n,n,n). Reconstruction phenomena have been prominent in studies using gold single crystal electrodes. Several groups have investigated the anion-induced transformations of (5 X 20) to (1 X 1) structures for Au( 100) electrodes ( E 2 1 4 E21Z). In a STM study, Gao and Weaver found that, in the presence of iodide, the conversion of the square planar (1 X 1) surface to a hexagonal reconstructed phase was remarkably rapid ( Ag( 100) > Ag( 1 10) > chemically polished Ag > mechanically polished polycrystalline Ag in KI solution (E257). STM of Pb UPD on Ag( 100) and Ag( 1 1 1) electrodes revealed formation of well-ordered monolayers (E258). Electrochemical reordering of a disordered palladium oxide surface was demonstrated by McBride et al. (E259). They found that treatment of a disordered oxidized surface with dilute NaI solution at a potential where oxide was reduced resulted in the appearance of the LEED pattern of a Pd( 100) surface. The same laboratory reported reorganization of surface bonding structures upon oxidation of CO adsorbed on Pd( 1 11) (E260) and the dissolution of Pd in a layer-by-layer process without loss of an iodine monolayer on a Pd(ll1)iodine surface (E261). Two-stage adlattice formation was suggested for the UPD deposition of Cu on Pd( 100) (E262), and thin Pd overlayers electrodeposited on Au( 11 1) and Au( 100) electrodes were shown to behave in a manner similar to Pd( 11 1 ) and Pd( loo), respectively (E263). Differences were found in the measurement of C O surface coverage values on Rh( 100) electrodes by coulometric and FT-IR spectroscopic techniques (E264). Adsorption of bisulfate on Rh( 11 1) featured adsorption plateaus over a wide potential range, in contrast to the behavior at polycrystalline Rh electrodes (E265). Perchlorate anions were reported to decompose on polycrystalline Rh and Ir( 1 1 1) electrodes to
produce a surface species, probably adsorbed chloride, that inhibited hydrogen adsorption (E266). Only negligible electrocatalysis was seen for the oxidation of methane when surface oxides and/or silver were deposited on Ru(001) electrodes (E267). Wang et al. have described a neat procedure for the preparation of Ni( 11 1) surfaces for electrochemical study. The surfaces, which were formed under UHV conditions, were protected with a layer of adsorbed CO prior to transfer to solution and electrochemical stripping of the C O (E268). The UPD of T1 and Pb on Cu( 111) films evaporated on mica surfaces was reported (E269), and an AFM study of potential-controlled oxygen adsorption on Cu(100) has appeared (E270). STM images were obtained of the silicon( 11 1) hydride phase that was revealed when an oxide layer was removed under potential control in HFg,) solution (E271). Surface Imaging Techniques. As is evident in the previous section, surface electrochemists have been applying the various surface microscopies to the study of electrode interfaces since the initial introduction of these techniques. The student wishing a more complete compilation of references on this topic should scan citations from the above sections on UMEs and single crystal electrodes. The articles mentioned here are perhaps more technique oriented, although the distinctions are often arbitrary. Vogel et al. published beautiful S T M images of Pt single crystal electrodes subjected to the “iodine procedure” both in air and in electrolyte solutions (E272). The images, which were in accord with previous LEED ex situ results, were obtained using a noncommercial STM apparatus, details of which were given. A prospectus for STM/electrochemistry has been published that contains many examples and impressive STM images (E273). Schmickler and Widrig presented some theoretical considerations of the STM/Echem experiment (E274). The Poisson-Boltzmann equation was solved for a sphere-plane configuration as a model for the tipsubstrate geometry (E275). Techniques for STM tip sharpening and related applications were extensively reviewed (E276). A combination of normal sharpening procedure under ac voltage with the tip oriented downward, followed by further sharpening with the tip oriented upward, was found to be effective for tungsten tips. Oxide layers on tungsten tips are easily removed in concentrated H F (E277). Details were given for the preparation of STM tips with reduced capacitive currents for use in a differential conductance mode of operation (E278)and for electrocoating STM tips with polyacrylic carboxylic acid (E279). Surface microscopes have been used in novel ways to characterize and/or to spatially modify film electrode interfaces. For example, Murray’s group has reported a procedure to produce spatially patterned, laterally heterogeneous polymermodified electrodes using in situ AFM (E280). They used an AFM tip to “nanodose” a defect in a thin film of insulating poly(pheny1ene oxide) (PEO). The defects were then filled by electropolymerized conducting polymers. Yang et al. proposed a STM technique to measure the thickness of polymer films on conducting substrates. The plot of tip current vs tip displacement exhibited linear regions due to (i) approach to the surface, (ii) penetration through the film, and (iii) contact with the substrate (E281). In situ AFM was successfully
used to follow the electrochemical formation of PEO (E282), while S T M images of poly(N-methylpyrrole) were noisy, probably because the STM tip typically was buried in the poorly conducting polymer film (E283). Sugimoto et al. used the Bard SECM technique in a directscanning mode to obtain images of a Prussian blue film electrode that showed cracks and grain boundaries at the submicrometer level (E284). Engstrom et al. employed SECM to map the local electron-transfer kinetics of reactions occurring at kinetically heterogeneous Pt disks or epoxy impregnated RVC electrodes (E285). Several other applications of the SECM technique have been cited above in the sectionon UMEs. The improvement in the technique involving small-amplitude modulation of the tip position seems especially important (B75,E286). This permits automaticdetermination of whether a surface is insulating or conducting. Among the many applications of STM to electrochemistry are several reports of STM images of dissolving electrodes (E287, E288), of metal particles deposited in the pores of anodic aluminum oxide films (E289),and of electrochemically grown organic semiconductors (E290). In situ STM/Echem of silver electrodes revealed time-dependent smoothing of the surface during redox cycles (E291), and the fractal dimensionality of Au and Pt electrodeposits was determined (E292). STM images of DNA molecules have been obtained on Au(ll1) surfaces under potential control (E293). This particular application, and related methodology (E294), promises to become popular in molecular biology fields. Fluorescence imaging of electrode surfaces was achieved by generation of OH- in weakly buffered solutions of fluorescein. Thus, reduction of H2O or 02, the latter at cathodic corrosion sites, converted the dye into a strong fluorescing species and produced images of the electrode surface (E295). Miller et al. imaged L-B monolayer films of a Ru-bpy surfactant by observing ECL with a sensitive CCD camera (E296). Finally, local ac impedances were obtained by measuring the potential difference between two microelectrodes in a probe assembly (E297). PolycrystallineElectrodes. An interesting comparison of chronocoulometry, radiochemistry, and Raman spectroscopy applied to the measurement of pyridine adsorption on gold electrodes has appeared (E298). Agreement was found between surface concentrations determined by the first two techniques, but chronocoulometry, where double-layer, not faradaic, charge densities were measured, gave the better precision. Adsorption of HS04-, C1-, and I- on Pt was measured by three in situ methods: radiotracers, FT-IR, and ellipsometry (E299). Bell-shaped adsorption isotherms were reported for 20 organic compounds on Pt (E300),and the Epzc values and capacitance minima for Au were measured in NaF(,,) using a piezoelectric technique (E301). An extensive set of double-layer data at various metal electrodes in DMSO, DMF, PC, AN, MeOH, and H 2 0 was collected and used to analyze metal/solvent interactions and the interfacial solvent structure (E302). Among the papers on the oxidation of methanol at solid electrodes are a study at mixed oxides of Pt and Sn (E303), a study of the effect of Ru deposition where RuOHad, intermediates were proposed (E304),a study of the effect of adsorbed Sn atoms (E305), a detailed examination of the Analytical Chemistty, Vol. 66, No. 12, June 15, 1994
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process at Pt-Ru alloys (E306), and a report of the use of hydrophobic nickel electrodes coated with fine particles of tetrafluoroethylene (E307). In situ FT-IR spectra revealed several intermediates in the process at Pt, including three forms of adsorbed CO, a COH species, and a CH-containing species (E308). Surface-enhanced Raman spectra also have been obtained for this system (E309). The surface electrochemical behavior of three isomeric pyridyl hydroquinones at polycrystalline Pt (and at P t ( l l 1 ) ) was dependent on the orientation of the adsorbed monolayers (E310). Oxidation of ethylene glycol gave different product distributions on Au, Pt, and Ni electrodes (E311). FT-IR spectra indicate C2 solution intermediates in route to oxalate and carbonate ions on gold electrodes, while formate was formed to the greatest extent on Ni. The electrocatalytic oxidation of toluene was seen at coatings of deposited hydrated platinum oxides on Pt, Ni, Ti, Fe, and glassy carbon supports (E312). Two pathways were described for the oxidation of phenol at Pt: one occurring at the inner Helmholtz plane, where ring cleavage took place, and one occurring at the outer layer, where a mixture of products was formed (E313). Squaric acid oxidation on Pt gave extensive formation of toads and COz products over a wide potential range (E314). Oxidation of surface mercaptoethanol films at Au proceeded by multiple pathways (E315). Evidence was presented to indicate that the first monolayer of adsorbed thionine is electroinactive at Pt. On sulfurmodified Pt, however, the first layer of adsorbed material is electroactive (E316). In similar fashion, sulfur adlayers on Pt changed the irreversible phenothiazine oxidation into reversible CV behavior (E317 ) . RDE and QCM measurement gave new insights on the well-studied iodine/iodide system at Pt in H2S0qaq)(E318). Michelhaugh et al. found that even submonolayer coverages of adsorbed iodine gave fast kinetics for the quinone/ hydroquinone couple, which they took to indicated selective ET at iodine surface sites (E319). Anodic 0-atom transfer electrode reactions were proposed for the oxidation of I- to IO3- at Pt, Au, Pd, Ir, and glassy carbon (B117),for anodic reactions at PbOz electrode doped with acetate (E320), for the oxidation of oxysulfur anions at PbO2 (E321),and for the determination of As(II1) at Pt where a key role was assigned to PtOH (E322). Anodic Cl2 evolution at Pt was reported to take place on an oxide-freesurface in anhydrous trifluoroacetic acid (E323). Oscillating phenomena continue to stimulate electrochemists, who have usually fingered CO,d, as a key intermediate in their mechanistic speculations (E3244E327). Wolf et ai. modeled the oscillating electrochemical reduction of peroxodisulfate by a system of nonlinear differential equations based on a Nernst diffusion layer treatment for a diffusion current term and a Butler-Volmer expression with a Frumkin correction for the charge-transfer term (E328). Good agreement between theory and experiment was obtained. The potential oscillations seen in the galvanostatic oxidation of formic acid on Pt were directly coupled to frequency oscillations in the EQCM experiment (E329). Finally, a true ac battery was based on an ingenious concentration cell that consisted of two mass-coupled oscillating half-cells. Typical specifica382R
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tions were period, 58 s; current, f 2 . 5 PA; and emf, f 5 0 mV (E330). The formation and growth of metal oxide films have been studied by a variety of methods including voltammetry, ac impedance, and EQCM. These include investigations of Pt electrodes (E331-E336), gold electrodes (E337-E340), and Pd electrodes (E341, E336). EQCM data indicated that the gold dissolution rate upon E cycling in H2S04(aq)was 550 ng/h (E337).
In the miscellaneous category, the relationship of area to volume of dendritic Ag deposits on polycrystalline Pt was found to exhibit fractal behavior with area = k ( ~ o l ) ~where /~, D = 2.50 f 0.03 (E342). This value is consistent with a self-similar fractal surface. Finally, a description of a guillotine electrode, which was tested on A1 electrodes in aqueous solution, was noted (E343). Miscellaneous Electrodes. Several reports have appeared that featured superconducting working electrodes. Plots of cdl vs T for two T1-based high-T, superconductors immersed in fluid electrolyte solutions displayed abrupt changes in the region of Tc ( E 3 4 4 ) . An increase in faradaic current was observed for high- Tc superconducting electrodes in contact with Ag+ ion conductors at low temperatures ( E 3 4 5 ) . A role was suggested for Cooper pairs crossing the double layer and participating in the electrode reaction. A quasi-reversible, almost irreversible, CV for the ferrocene+/O couple was obtained at a Bi-Pb-2223 superconducting UME at 102 K (E346). Kuznetsov developed theory explaining the increase in current in the Tc region for superconducting electrodes (E347). Conditions were given for the anodic electrosynthesis of millimeter-sized crystals of Bao.sKo.4BiO3with Tc values of 30.5 K (E348). Superconducting thin films of Y-Ba-Cu-0 and T1-Ba-Ca-Cu-0 were electrodeposited at negative potentials in DMSO solution (E349). Electrochemical Lidoping of high- Tcsuperconducting films resulted in an increase in a lattice constant and/or the T, value (E350). Electropolymerization of aniline on the surface of YBa2Cu3O,-a produced a film with protective properties (E351). More interestingly, redox cycling of poly(pyrro1e) coated on thin superconducting films reversibly changed the Tc value by almost 15 K (E352). The Cu(III/II/I) system was examined at the latter surface (E353), and Ma et al. successfully electrodeposited Cu contacts onto a superconducting substrate (E354). Several interesting working electrode materials containing titanium have been studied in the last two years. Titanium diboride, an electroconductive ceramic, exhibited a wide potential window and was used for the reduction of C02 (E355). Ebonex, a conducting ceramic mainly composed of the Magneli phase of titanium oxides Ti407and TiS09,coated with PbO2, was found to be a suitable anode for ozone generation (E356). A previous report from Pletcher’s group had described conducting titanium oxide ceramic electrodes (E357). Polycrystalline thin films of cubic BaTi03 were prepared on Ti metal substrates by several methods, including an electrochemical anodization in Ba(OH)2 solution (E358).
F. MODIFIED ELECTRODES Charge Transport in Polymer Films. Several important papers on this topic have appeared in the last two years. Attention is also called to the review of Inzelt, who has surveyed theory and experiment up to ca. 1992 (A40). Fritsch-Faules and Faulkner simulated lateral charge transport in a thin film of redox centers electrostatically held in a polymer matrix ( F I ) . Their model allowed for partitioning between the film and solution, which opened two diffusional paths for the ions in the charge transport process. In a nice experimental study, they determined the concentration profiles in methylquaternized poly(viny1pyridine) (PVP) films containing the Fe(CN)&/”couple by means of potentiometric measurement at arrays of 4-pm-wide Au electrodes in contact with the film (F2). The concentration profiles under steady-state current flow between flanking electrodes were linear. The calibration curve relating potential to concentration was established by chronocoulometry in a companion paper (F3). The behavior was found to be Nernstian in spite of (i) different extent of partitioning of ferri- and ferrocyanide, (ii) oxidation-statedependent mass transport, and (iii) nonideal CV behavior. The charge transport was dominated by diffusion of the redox species through solution since the diffusion coefficients were 2-3 orders of magnitude greater in solution than in the film. The experiments of Larsson et al. (F4) on PVP films containing Fe(III/II) redox sites either directly bound to pyridine groups on the polymer or electrostatically bound to quaternary pyridinium sites relate to this model. In the former situation, the apparent charge-transfer diffusion constants (DcT)were almost 100times smaller than in the more typical ion-exchange polymer. The dynamics of electron hopping in assemblies of redox centers has been treated in a major contribution that is pertinent to charge transport in fixed-site redox polymers (F5). The authors found that when physical motion of the redox centers was either nonexistent or much slower than electron hopping, charge propagation was fundamentally a percolation process, in which electron hops occur between a random distribution of redox center clusters. In another paper, Blauch and Saveant modeled the charge transport by random walk of electrons through redox molecules in square and cubic lattices (F6). Below a critical concentration, finite cluster size makes charge transport impossible. Further, in their treatment, the mean-field physical diffusion model of Dahms and Ruff was shown to be inapplicable to systems in which the contribution of physical diffusion to charge transport is small compared to that of electron hopping. Rapid bounded diffusion in systems where the redox centers are irreversibly attached to the supramolecular structure, on the other hand, gives rise to mean-field behavior when it exceeds the rate of electron hopping. In another approach, Mohan and Sangaranarayanan incorporated an exponential dependence of electron hopping rates on distance into a generalized diffusion/migration equation for redox film charge transport (F7). Also Deiss et al. published a quitegeneral digital simulation of redox polymer CVs (F8). Their calculation accounted for mass transport by diffusion and migration, electron hopping by a Saveant mechanism, homogeneous reactions in the film, heterogeneous reactions and C,-Jat the membrane/electrode interface, and
Donnan partitioning at the membrane/diffusion layer interface. Impedance techniques have been refined for the analysis of charge transport in polymer film electrodes and successfully applied, notably by Pickup and Albery and their respective co-workers. Ren and Pickup have published several studies where they used a transmission line equivalent circuit to analyze charge transport in ion exchange polymers based on poly(pyrro1e) (PPy) (F9-FI 1). They employed a porous electrode model and generally found that ion mobility limited the charge transport. A good example is their study of polymer films of 3-methylpyrrole-4-carboxylicacid, where ion mobility was lo3faster than electronic conductivity (F9). The results were interpreted using a two-phase model in which ion transport was due to counterions in the polymer phase and excess electrolyte in the pores. Fletcher also used a porous electrode model to interpret impedance data for conducting polymer electrodes (F12, F13). In a similar fashion the transmission line model of Albery and Mount was based on a porous electrode with organic polymer and aqueous pore phases (F14). Resistances were obtained due to bimolecular electron exchange and anion buildup in the film. In another treatment of polymer film ac impedance, they proposed a transmission line model in which there were separate resistive rails for the cation and for the anion (F15).This would apply to the common situation when electron motion along the polymer backbone is faster than ion conduction in the pores. Mathias and Haas have developed theory for ac impedance of redox polymer films under conditions where either electron hopping or ion migration is slow relative to the other (F16). They assumed Donnan exclusion permitting only one mobile ion in the film. These authors have studied PVP films containing Os(bpy)z centers under conditions of four bathing electrolytes where the charge transport was via electron and anion motion only (F17). (This paper gives a nice summary of the procedures for extracting parameters from raw impedance data.) In contrast to the above situations, ion transport in these films was found to be much faster than electron hopping, even for large anions such as toluenesulfonate. The impedance response of poly(pyrro1e) bilayers, with perchlorate and poly(styrenesu1fonate) counterions, indicated that the redox reaction was outside-inside, i.e., began at the polymer/solution interface (F18). This was consistent with a porous electrode model and with the redox polymer model of Albery et al. (F19). On the other hand, a chronopotentiometric study concluded that an inside+mtside mechanism was operative for lightly doped PPy (F20). Sharp et al. gave a clear account of the interpretation of impedance data for Nafion film electrodes containing O~(bpy)3~+/*+ and substituted ferrocene couples (F21). The dependence of the redox conductivity on the overall oxidation state of the film, in their view, was in agreement with an ion-pairing model in which electron hopping took place between, for example, a neutral Os(I1) site and a positive Os(III)+ site. Forster and Vos have reported correlations between DCT and the heterogeneous electron-exchange rate( k o )for two redox polymers containing Os(III/II)-bpy sites (F22, F23). The effect of the extent of loading of O~(bpy)3~+/*+ in Nafion was significant when the amount of Analytical Chemistry, Vol, 66, No. 12, June 15, 1994
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Os was greater than one-third of the available anionic groups necessary for charge neutrality in the oxidized state. In this case, the CVs exhibited two waves: a reversible surface wave for the Os(III/II) couple and an irreversible wave at greater potentials that involved ejection of the complex from the film (F24). The ejection was elegantly verified by SECM using a UME probe positioned above the film. Mao and Pickup used RDE voltammetry of ferrocene to measure the potential profile across a substituted poly(pyrro1e) film. The gradient was nonlinear, which they took to indicate nonmetallic conductivity where the charge transport process is driven by a concentration gradient of oxidized sites in the polymer matrix ( F 2 5 ) . Aoki and Heller measured apparent electron diffusion coefficients in a cross-linked redox polymer that contained Os(bpy)2 redox sites. In their interpretation of the data, they invoked hydration effects that were induced by counterions, ionic strength changes, or protonation of basic groups on the polymer backbone (F26). Water transport was noted in EQCM studiesof PVPfilms containing Os(III/II)-bpy centers (F27) and poly(viny1ferrocene) films (F28, F29). Slow structural changes for related polymer films were seen when the electrodes were transferred between perchloric and toluenesulfonic acid solutions (F30). For poly( l-hydroxyphenazine) films, the typical featureless CV was shown to involve two ion-exchange coupled steps: one with proton transport and the other with anion uptake and solvent loss (F31). Hydration effects were also noted for the solid-state charge transport in hexacyanoferrate films with fixed Fe(III/II) sites ( F 3 2 ) . An equivalent circuit proposed for the interpretation of impedance data at redox polymer electrodes contained two capacity terms: one for the substrate/polymer interface and one for the polymer/solution interface (F33). Also the effect of surface roughness of the substrate on the impedance of polymer films has been considered ( F 3 4 ) . The combination of ac impedance spectroscopy and "electromodulated optical transmittance spectroscopic impedance" was used by Amemiya et al. to study charge transport in polymer film electrodes (F35, F36). Hillman and Bruckenstein have pointed out the important role of slow solvent transport in several studies of the redox kinetics of permselective polymer films. Electron transfer, solvent uptake, and polymer reconfiguration in a cube scheme were incorporated into a general model (F37). Often observed phenomena such as "break-in" processes, charge and mass trapping, structural changes with redox cycling, and variation of charge transport rate and Eo' values with time were encompassed by their theory. For a polythionine redox film, the kinetics were described in terms of a scheme of squares involving electron, proton, and solvent transfer (F38). The EQCM data showed that the coupled motion of electrons and protons preceded the rate-limiting solvent transfer in both anodic and cathodic steps. One of the later papers in the general Bruckenstein and Hillman treatment of the EQCM experiment has appeared in the last two years (F39). Proton transfer was also shown to be involved in the charge transport process operative in thin ubiquinone-Qlo films ( F 4 0 ) . A two-phase model was employed to explain the surprisingly large electrochemical diffusion coefficients in polyacrylate 304R
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gels ( F 4 1 ) . In spite of high gel viscosities, high diffusivity in thecontinuous aqueous phase was invoked to explain the data. Electrocatalysis at Modified Electrodes. This subject, a raison d'stre of modified electrode research, has seen relatively little theoretical activity in the last two years. The general treatment of electrocatalysis at polymer-modified electrodes containing microparticles stands out however ( F 4 2 ) . Equations were derived for the flux as a function of the number of particles per unit volume, the film thickness, the substrate and mediator concentrations, and the particle radii. Eight cases were described, along with the respective flux equations, that differed in the reaction orders with respect to the above experimental variables. In a second paper on metal oxide/ Nafion composite amperometric sensors, the kinetics were cast in the context of the Michaelis-Menten formalism (F43). Anson and Xie have addressed several important aspects of data analysis for the estimation of rates of cross-reactions that occur during electrochemical catalysis at polymermodified electrodes using the Koutecky-Levich equation (F44, F45). In a later paper, a modified kinetic model, which assumed an array of film mediator couples with a Gaussian distribution of Eo' values, was developed (F46). When the parameters of the distribution were selected to fit the i-E curve for the non-Nernstian surface wave of the mediator couple, significant improvement in the agreement between experimental and calculated currents was obtained for several cases involving redox couples in Nafion coatings. Numerous articles continue to be published on various polymer-modified electrodes designed to be catalytic for specific processes. The ones cited here will be organized in terms of the electrode reaction catalyzed and not by the nature of the polymer matrix. Electrocatalysis of 0 2 reduction was achieved at a porphyrin ligand coordinated by four Ru(NH3)5 groups in Nafion (F47), and by metal phthalocyanines in various matrices (F48-F50). Cobalt(I1) complexes in Nafion ( F 5 1 ) and Prussian Blue/poly(aniline) (F52) films catalyzed the reduction of C02. Electrocatalytic reduction of nitrite took place at quite positive potentials at PVP films containing Os-bpy complexes (F53, F54);a mixture of N20, N2, NH2OH, and NH3 was obtained at thin polymeric films of an iron(II1) protoporphyrin (F55).Oxyanions such as chlorate and bromate were reduced at conducting polymer electrodes doped with molybdate species (F56,F57). Poly(pyrro1e) films were robust enough to mediate the reduction of dichromate in acid (F58).Electrocatalytic films for the reduction of the disulfide bond in cystine (F59)and for the Cu(II/I)-mediated reduction of cytochrome c and tyrosinase (F60) have been described. Substituted poly(pyrro1e) films with Pd(I1) and Rh(II1)-bpy centers were used, respectively, for the hydrogenation of organic compounds (F61) and the catalysis of hydrogen evolution (F62). Catalytic activity was imparted to insoluble liquid crystal films of a cationic surfactant on graphite electrodes by vitamin B I Zhexacarboxylate (F63). On the oxidation side, several different polymer film electrodes have been used for the electrocatalytic oxidation of NADH (F64-F66). Pyrrole-substituted Mn tetraphenylporphryrins were precursors to catalytic polymer films for the epoxidation of alkenes and the oxidation of thioacetamide (F67). Ru(V/IV)-oxygen complexes in Nafion and poly(pyrrole) films mediated the oxidation of alcohols (F68,F69).
Electropolymerization of several free-base and metalated porphyrins produced conductive redox polymers with electrocatalytic activity for a variety of reactions (F70,F71),and a porous Ti02 ceramic coated with Nafion containing RuOz/ IrOz catalyst was an efficient electrode for oxygen evolution (F72). Polymer film matrices have been employed in enzyme electrodes since the initial work on things such as the urease electrode of Updike and Hicks. The use of redox polymers and conducting polymers in conjunction with mediating species continues to be an active research area. Many different variations, and some not so different, have been published in the last two years on this topic, especially with glucose oxidase as the enzyme system. Only a few of these will be mentioned here. Ye et al. described a glucose electrode, which was made with Heller’s epoxy redox polymer and a quinoprotein glucose dehydrogenase, that exhibited exceptionally high current densities, 1.8 mA/cm2 (F73). An improved glucose sensor was fabricated via the substituted pyrrole route using glucose oxidase that had been covalently modified with pyrrole (F74). Your reviewer also liked the description of a glucose sensor “switch” that was based on a poly( 1,2-diaminobenzene) film containing the enzyme, which was polymerized on top of a poly(ani1ine) electrode (F75). Another crafty approach was that of Anzai et al. who electrodeposited avidin on Pt and then complexed the surface with biotinylated glucose oxidase (F76). The mediated redox enzyme concept has been applied to enzyme systems other than glucose oxidase to develop sensors for other species including amino acids (F77),fructose (F78), lactate (F79),NADH (F80), and others (F81). Papers also continue to appear on electrocatalytic applications of surface-modified electrodes without a (often resistive) polymer film component. Some of these have been cited under Carbon Electrodes. Shi and Anson have studied their cobalt porphyrin substituted with Ru(NH& groups via pyridyl ligands when it is adsorbed on graphite (F82). The currents for oxygen reduction were greater at these surfaces than at Nafion film surfaces containing the same complexes, but the stability was not as good. In another study it was found that the number of Ru(NH& groups on the complex determined whether a two-electron or a four-electron pathway was followed (F83), with the trisubstituted pomplex giving the latter behavior. For protoporphyrin IX-modified glassy carbon electrodes a two-step reduction of 0 2 was observed for pH >12, and a four-electron reduction for pH 4, the nitro group was reduced to form a nitrosamine. Mirallesroch et al. (H26)examined the electrochemical conversion of a-nitrobenzylic compounds into the corresponding oximes. Anne et al. (H27, H28)examined the electrochemistry of synthetic analogues of NADH and NAD dimer analogues. Medebielle et al. (H29) investigated the perfluoroalkylation
of pyrine and pyrimidine bases by electrochemically induced SRNI substitution. Combellas et al. (H30) carried out selective substitutions of 1,4-dichlorobenzene with 2,6-di-tert-butylphenoxide using the electrochemically induced S R Nmecha~ nism. Mortensen et al. ( H 3 I ) studied the voltammetry of highly reduced oligoanthrylene systems and were able to generate the tetraanion of all the species studied. Cleghorn and Pletcher reported on the mechanism of the electrocatalytic hydrogenation of organic molecules at palladium black (H32) and palladium on nickel cathodes (H33). Mahdavi et al. (H34) examined the electrocatalytic hydrogenation of phenanthrene at Raney nickel electrodes. The electrochemical fluorination of benzene was carried out at +2.5 V in acetonitrile using tetraalkylammonium fluoride salts (H35). Delgado et al. (H36) examined the electrochemistry of an alkali metal complex of quinone crown ethers and showed that the formation constants with the alkali metal with the attached crown ether varied with the redox state of the quinone. The binding of the alkali metal was qualitatively and quantitatively different from simple ion pairing. Urove and Peters (H37)examined the electrochemical reduction of cyclohexanecarbonyl chloride at mercury cathodes. Pritts et al. (H38) reported on a method to quantitatively determine volatile products formed in the electrolysis of organic compounds. Wandlowski et al. (H39) studied the electrochemical oxidation of 2,6-dichloro- 1,4-phenylenediamine. Potential step and digital simulation of the voltammetric data was used to determine the kinetic parameters. OrganometallicElectrochemistry. Redox-induced changes in the conformation, bonding, or solvation of the metal atom of a complex can be readily probed by the use of electrochemical techniques. Electron-transfer-induced isomerization of cobalt, nickel, and palladium cyclooctatetraene complexes was examined by Geiger et al. (H40). The Ni and Pd complexes retained their 1,5-conformation upon reduction, while the Co complex underwent rapid isomerization to the 1,3-isomer in the 19e-species. The differences were explained by the role played by the ligand vs metal composition of the redox orbital. Osella et al. reinvestigated the electrochemical behavior of the Coz(CO)b(ethynylstradiol)complex and found evidence of efficient recombination of the electrogenerated fragments (H41). They also found electrochemical evidence for the reorientation of alkynes on trimetallic clusters during a two-electron reduction (H42). Karpinski and Kochi (H43) used electron-transfer chain (ETC) catalysis in the electrochemical deligation of bis(arene)iron(II) dications. Mechanistic studies were carried out using normal and reverse-pulse voltammetry. Sanaullah et al. (H44) used chemical and electrochemical methods to examine the redox-associated conformation changes in the bis( 1,4,7-trithiacyclononane)copper(II/I) system. Electrochemical studies on nioboceneketene complexes yielded redox-induced ketene fragmentation reactions (H45). Solvent effects on the redox behavior of organometallic complexes were examined by several groups. Boudon et al. (H46) studied the effects of axial anions and solvent on the redox behavior of nickel complexes with C-functionalized tetraazamacrocycles. McDevitt and Addison (H47) examined medium effects on the redox properties of tris(2,2’-bipyridyl)ruthenium complexes. The medium was also found to Analytical Chemistry, Vol. 66,No. 72, June 75, 1994
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modulate the two-electron activity of ferrocene metallocyclam conjugates ( H 4 8 ) . Mu and Schultz ( H 4 9 ) studied the effect of methanol binding on the redox potential and electrontransfer reactivity of chloro(tetrapheny1porphinato)manganese(111).
The use of inert solvents such as liquid sulfur dioxide and/ or microelectrodes has enabled the voltage range to be extended, and highly reduced or oxidized species were observed. Liquid sulfur dioxide was used to study the oxidation of M(b~y)3~+complexes where M = Ni, Zn, and Cd (H50,H 5 1 ) . Very negative and very positive potentials wereused to generate Cp2C02+,Cp2C02-, and Cp2Ni2- ( H 5 2 ) . Ruthenium complexes are quite interesting in that they can undergo a large number of redox processes. Four one-electron-transfer steps were observed in the voltammetry of truns-[R~(tpy)(O)~(H20)l2+(H53). Ruthenium(I1) complexes of 2,2’-bipyridine and 2-pyridylpyrazine were examined up to -3.1 V a t -54 OC in D M F using cyclic voltammetry ( H 5 4 ) . By the use of convolution techniques and digital simulation, it was possible to determine between 8 and 12 redox steps, depending upon ligation. Krejcik and Vlcek (H55)found that [(Ru(bpy)2)zbpml4+ yielded 14 one-electron waves, 2 of which were metal based and 12 ligand based. Deblas et al. ( H 5 6 ) used pyridines with appended metallocyclam subunits as versatile building blocks to supramolecular multielectron redox systems. Reversible electrogenerated triply oxidized nickel porphyrins and porphycenes were reported by Kadish et al. ( H 5 7 ) ,where they were able to generate a stable nickel(II1) x-dication. The oxidation state of the metal atom in the electrogenerated complex was the focus of several studies. Guldi et al. (H58)investigated whether chromium(II1) porphyrins were reduced to Cr(I1) porphyrins or Cr(II1) porphyrin r-cation radicals. Kadish et al. ( H 5 9 ) examined the site of electroreduction of rhodium porphyrins. A very complex redox scheme was elucidated for the reduction of a-bonded iron(II1) porphyrins in noncoordinating solvents ( H 6 0 ) . Strojanovic and Bond ( H 6 1 ) examined the conditions under which the reduction of cobaltocenium cation could be used as a standard voltammetric reference process in organic and aqueous solvents. Kaminsky et al. ( H 6 2 ) reported on a reference electrode for organic solvents based on modified polyethylenimine loaded with ferrocyanide/ferricyanide. Inorganic Electrochemistry. The electrochemistry of buckminsterfullerene and related complexes attracted the attention of many researchers. Xie et al. ( H 6 3 )detected the hexaanions, c606- and C706-, using electrochemistry . The electrochemistry of c 6 0 was also studied in liquid ammonia ( H 6 4 ) . The kinetics and thermodynamics ( H 6 5 )and the role of solvation ( H 6 6 ) in the electroreduction of c60 in aprotic solvents was investigated. Fast-scan cyclic voltammetry and scanning electrochemical microscopy ( H 6 7 ) were used to determine the kinetic parameters for the electroreduction of c 6 0 . An electrochemically reversible oxidation of c 6 0 and C70 was reported ( H 6 8 ) ,as was the electrochemistry of C60H2 ( H 6 9 ) . Penicaud et al. ( H 7 0 ) electrocrystallized c 6 0 for the synthesis andcharacterization of (Ph4P)2C6oIX. Li et al. ( H 7 1 ) reported on unusual electrochemical properties of the chiral c 7 6 . Lerke et al. ( H 7 2 ) studied platinum, palladium, and nickel derivatives of buckminsterfullerene. Three to four waves 406R
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were observed, and the initial reduction led to the loss of the metal fragment. Koefod et al. ( H 7 3 ) studied the electrochemistry of an iridium buckminsterfullerene complex and found evidence for a c60 localized reduction. Sudha et al. ( H 7 4 ) reported on electrochemical evidence for a two-electron-reduction process in a p-oxobis(F-acetate)diruthenium(II1) complex with a terminal 1 -methylimidazole ligand. The electrochemistry of the incomplete cubane-type clusters, M3S4 ( M = Mo, W), was examined ( H 7 5 ) ,as well as some molybdenum mononitrosyl complexes containing oxobiphenyl ligands ( H 7 6 ) . The influence of pyridine substituents on binuclear rhenium(V) clusters was studied as a redox tuning procedure ( H 7 7 ) . Low-temperature voltammetry was used to study the reduction and oxidation of [ Re2(NSC)g] 2- (H78). The electrochemical reduction mechanism of a Ru3(C0)12 was investigated in considerable detail by voltammetric techniques ( H 7 9 ) . Cyr et al. ( H 8 0 )studied the electrochemistry of boron-capped 99Tc-dioximecomplexes. Choi et al. ( H 8 1 ) studied the electrochemical reduction of thionyl chloride by cyclic voltammetry, chronocoulometry, and chronoamperometry. Opekar and Langmaier ( H 8 2 ) reported a procedure for electrochemically controlled generation of carbon monoxide. Activation of Small Molecules. The direct electrolysis or electrocatalytic activation of small molecules has been an active area of research. The largest area is probably the activation of carbon dioxide. These studies have involved both the direct reduction of carbon dioxide and the coupling of C 0 2 to a substrate. Reports on theelectrocatalyzed reduction of carbon dioxide have included the catalysis by molybdenum-ironsulfur clusters ( H 8 3 ) ,nickel phosphine clusters ( H 8 4 ) ,iron, cobalt, and nickel terdentate complexes ( H 8 5 ) , osmium bipyridyl complexes ( H 8 6 ) ,and rhenium bipyridyl complexes incorporated into a coated Nafion membrane ( H 8 7 ) . Electrocatalytic surfaces have been reported for the direct reduction of carbon dioxide, such as ruthenium-titanium oxide ( H 8 8 ) , Cu + Au electrodes ( H 8 9 ) ,Perovskite-type electrocatalysts ( H 9 0 ) ,palladium ( H 9 1 )or copper-modified palladium ( H 9 2 ) electrodes, and nickel electrodes a t high pressure ( H 9 3 ) . Carbon dioxide may also be electrochemically activated by the reductive addition of CO2 to quinones in acetonitrile (H94). Carbon dioxide can be coupled electrochemically by a nickel catalyst to 1,3-enynes ( H 9 5 ) ,diynes ( H 9 6 ) ,or alkenes ( H 9 7 ) . p-Anisic acid was formed from the reduction of p-iodoanisole at mercury in DMF, saturated with carbon dioxide ( H 9 8 ) . The electrocatalytic generation of C2 and C3 compounds was reported for the reduction of C 0 2 on a cobalt compleximmobilized dual-film electrode ( H 9 9 ) . Kyriacou et al. (H100) examined the influence of CO? partial pressure and the supporting electrolyte cation on the product distribution. Naitoh et al. (H101) studied the electrochemical reduction of carbon dioxide in methanol a t low temperature. The electroactivation of other small molecules have also been reported. Formaldehyde was oxidized on ultrafine gold particles, supported on glassy carbon substrates (H102). Methanol was electrooxidized on rhenium-tin oxide, platinumtin oxide, and iridium-tin oxide, and the results were compared with the oxidation on platinum (H103). The electrocatalytic oxidation of methanol at PTFE-bonded electrodes was studied for a direct methanol/air fuel cell ( H 1 0 4 ) . Wong et al.
reported on the electrocatalytic oxidation of methanol (HZ05) and benzyl alcohol (HZ06) with a monooxoruthenium(V) complex. Cavalca et al. (HZ07) examined electrochemical modification of methanol oxidation selectivity and activity on a platinum single-pellet catalytic reactor. Gasteiger et al. (HZ08)studied methanol electrooxidation on well-characterized Pt-RN alloys. A quadruply aza bridged closely interspaced cofacial porphyrin was used to catalytically reduce dioxygen (HZ09). A rotating disk electrode was used to study the catalytic alkaline cyanide oxidation (HZZ0).A cobalt(111)-mediated electrochemical oxidation was used to destroy chlorinated organics (HI Z I). F430-Model compounds, which contain nickel isobacteriochlorins, will dehydrohalogenate alkyl halides (H1Z2). Lojou et al. (HZZ3)examined the electroreduction of aryl halides in D M F on a cadmiummodified gold electrode. Che and Dong (HZZ4)applied ultramicroelectrodes to the electrocatalytic reduction of organohalides by metalloporphyrins. The electrocatalytic reduction of nitrate was studied with foreign lead adatoms (H115).Gur and Huggins (HZZ6)studied the direct electrochemical conversion of carbon to electrical energy in a high-temperature fuel cell. Electrosynthesis. Electrosynthetic procedures have often been the impetus for detailed mechanistic studies by electrochemical techniques. The interplay between electrosynthesis and electroanalytical studies has been quite synergistic over the years. One area of active research is the direct electrosynthesis of solid material. Matsumoto et al. (HZZ7) reported a new preparation method of Lac003 Perovskite using electrochemical oxidation. Wade et al. (HI 18) electrosynthesized ceramic materials and precursors, while Singh and Tanveer electrosynthesized (CdHg)Se (HZ19, HZ 20) and (ZnCd)Se (HZ2Z). Dennison (HZ22) studied the cathodic deposition of CdS from aqueous solution. Roberts et al. (HI 23) investigated the mechanism and electrosynthesis of the superconductor Bal,K,Bi03. The direct dissolution of solid electrodes has also been used electrosynthetically. Halo and mixed-halo complexes of palladium(I1 and IV) were synthesized by the dissolution of a sacrificial palladium anode (HZ24). Cathodic dissolution of an AuTe2 electrode led to the formation of A ~ 3 T e 4 ~(HZ25). Niyazymbetov and Evans (HZ26, HZ27) reported on the utility of carbanions and heteroatom anions in electroorganic synthesis. Biaryls and aromatic carboxylic acids were synthesized by palladium-catalyzed electrosynthesis using triflates (HZ28). Freshly metal coated electrodes were used to electrosynthesize 1,2-diketones by reduction of aromatic esters (HZ29). Gard et al. (H130) reported an efficient electrochemical method for the synthesis of nitrosobenzene from nitrobenzene. Momota et al. (HZ3Z)reported the electrochemical fluoridation of aromatic compounds in liquid R4NF.mHF. Wendt et al. (HZ32, HZ33) studied the anodic synthesis of benzaldehydes from the anodic oxidation of toluene. Amino acids were synthesized from a molybdenum nitride via nitrogen-carbon and carbon-carbon bond formation reactions involving imides and nitrogen ylides (H134). aNitrobenzylic acids were converted into oximes using macroscale electrolysis (HI 35). .The hydrodimerization of dimethyl maleate in methanol using an undivided cell was reported by Casanova et al. (HZ36). Franklin et al. (HZ37)
reported a method for the destruction of halogenated hydrocarbons accompanied by the generation of electricity. Kunai et al. (HI 38) synthesized poly(disilany1ene)ethylenes by the electrolysis of bis(chlorosily1)ethanes. Chakravorti et al. (HZ39)reported the first electrosynthesis of transition metal peroxofluorocomplexes (HZ39). The selectiveelectrosynthesis of (CH&C60 provided a novel method for the controlled functionalization of fullerenes (HZ40).Ferrate(V1) was prepared using an alternating current superimposed on the direct current (HZ4Z). Micelles and Surfactants. Micellar media can provide for some very interesting electrochemistry because of their ability to solubilize material in aqueous solutions. Nikitas (H142)reported a simple model for micellization and micelle transformations on electrode surfaces. Myers et al. (HZ43) studied solution microstructure and electrochemical reactivity. They examined the effect of probe partitioning on electrochemical formal potentials in microheterogeneous solutions. Abbott et al. (HZ44)studied electron transfer between amphiphilic ferrocenes and electrodes in cationic micellar solution, and the correlations between solvent polarity scales and electron-transfer kinetics, as applied to micellar media (HZ45). Gouniliet al. (HZ46) studied theinfluenceofmicelles and microemulsions on the one-electron reduction of 1-alkyl4-carbomethoxypyridinium ions. The rate enhancement and control in electrochemical catalysis using a bicontinuous microemulsion was examined (HZ47), and this method was used to debrominate alkyl vicinal dibromides with neutral metal phthalocyanines (HZ48). An adsorbed film of cationic surfactant was used to dechlorinate 9-chloroanthracene (HZ49). Takisawa et al. (H150)reported on ultrasonic relaxation and electrochemical studies of the micellization of sodium decyl sulfate and decyltrimethylammonium bromide in glycerol/water mixtures. Phani et al. (HZ51)developed a microemulsion-based electrosynthesis of polyparaphenylene.
I. SPECTROELECTROCHEMISTRY The following survey is organized principally by technique. While most spectroelectrochemical methods are well established, the cited articles either feature some experimental aspect of general interest or illustrate particularly well the versatility of a given technique. On-line electrochemical mass spectroscopy, which is a powerful technique for the study of complex electrode reactions of small molecules, has been applied to a variety of problems. Included among these are studies of redox reactions of alcohols on Pt and Au (11-13) and on carbon-based electrodes (14). The working electrode of the latter study was made from PTFE-bonded carbon supporting Pt and Pt-Ru catalysts on Norit BRX. The working electrode of Munk and Skou was a microporous gold film on a commercial silicone rubber membrane (15). E C / M S has provided detailed mechanistic insight into the role of surface structure at single crystal electrodes during electrode reactions of unsaturated compounds (E152, E153, 16). E C / M S studies have appeared on the oxidation of formaldehyde (Z7-110), acetonitrile (11I), DMSO and sulfolane (Z12),and propylene carbonate (113,114). The latter article provides a good example of the use of isotopicallylabeled Analytical Chemktry, Vol. 66, No. 12, June 15, 1994
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solvents (D2O and H2I80) to trace the origin of intermediates and products of the electrode reactions (114). An on-line EC/MS study of 0 2 reduction under conditions of a methanol fuel cell allowed parallel reactions to be sorted out (115). Information on the reductive pathways for CH3CC13 a t the Pt/H2S04 interface (116) and for nitrite at graphite-supported CuO electrodes (11 7) was obtained. A porous Ni-plated Teflon membrane allowed the electroless Ni-P deposition to be followed by mass spectroscopy (118). The oscillatory reaction involving bromate, malonic acid, and the Ce4+i3+couple was followed by potentiometry and mass spectroscopy. The production of COz(,) tracked the potential oscillations in this system (119). Several simplified designs of differential EC/MS interfaces have appeared (120,121). Articles continue to appear in which X-ray methods have been used to probe the electrode/solution interface. These techniques can give detailed specific information, i.e., bond lengths, in the best of circumstances, but require access to a synchrotron radiation source. Two new descriptions of cell designs for in situ X-ray spectroelectrochemistry were noted (122, 123). The latter employed transmission geometry through a drop of solution maintained on the electrode surface by capillary action. Adlayer formation via UPD of metals are well-suited to study by X-ray methods. Recent systems examined include theUPDofPbandThonAu(l11)(124),CuUPDonPt(lIl) (125) and Pt( 100) (126),Cu deposition on carbon-supported Pt (127),Ag UPD on Au( 11 1) (E234),and iodine adsorption on Pt single crystal electrodes (128). In the UPD study at Au( 11 l ) , it was found that the Au-Pb distance was potential dependent, while the Au-Th distance was not (124). I n the surface EXAFS study of Cu UPD, chloride ion was shown to play an important role in the ordering of the adlayer (125). In situ X-ray methods have been used to follow intercalation reactions of Moo3 (129),Li,CoOz (130), and V6OI3 (131) electrodes. In situ X-ray spectra demonstrated the conversion of cu-PbOz to the p-form on Pt substrates (132) and the formation of Cu20 layers by the reduction of Cu02’- in concentrated KOH (133). In situ XANES of Fe-26Cr stainless revealed peaks for Cr(V1) that could be correlated with the transpassive voltammetric wave (134).Near-edge EXAFS spectra demonstrated that disulfide bond scission occurred upon electroreduction of a sulfur polymer (135). In situ X-ray methods have monitored surface roughness ofPt(l11) andAu(IOO)electrodes(Z36.137)andtheformation of oxides on dispersed Pt/C fuel cell electrodes (138). Spectroelectrochemistry in the UV/visible region of the spectrum is routinely practiced in the characterization of inorganic, organic, and biological redox couples. On the theoretical side, Wei et al. have published several papers on spectroelectrochemistry under “long-path-length’’ conditions, i.e., with the light beam parallel to the working electrode (139-143). One of the papers contains theoretical expressions for derivative linear sweep and derivative cyclic voltabsorptometry, e.g., expressions for d(ABS)/dE],k, under thin-layer conditions (140). The case of semiinfinite linear diffusion was also addressed. The catalytic EC’ mechanism has also been treated under these conditions (144,145). Zamponi et al. have presented derivative linear sweep voltabsorptometry 400R
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theory for surface waves and OTTLE cells (146). The relationship between the d(ABS)/dt vs E curve and the corresponding voltammetric parameter is one of equivalence in most situations. A spectroelectrochemical sensor for Cl2 based on a planar optical waveguide was described (147). This novel device employed a thin Lu-biphthalocyanine film on IT0 that could be electrochemically reset to the reduced state. Oxidation of the film by dissolved chlorine, which was monitored at 950 nm, resulted in an integral signal that was linear in the 0-30 ppm range. The transmittance changes were detected using a transverse magnetically polarized evanescent wave. Wavelength modulation spectroscopy was used to obtain spectra of methylene blue and Co tetrasulfonated phthalocyanine couples on graphite electrodes (148).The instrument described had a resolution of ca. 0.002 absorbance unit. Several papers on experimental aspects were noted. A simple procedure was given for the synthesis of SnO2 and the preparation of SnO2-coated I T 0 glass electrodes (149). An optically transparent carbon film electrode, with electrochemical properties similar to glassy carbon, was prepared by the pyrolysis of an aromatic anhydride on a quartz substrate (150). The general method of modifying I T 0 electrodes of Chen et al. deserves mention again (F88). Salbeck has published two standard designs for thin-layer cells, in one of which only Teflon components contact the solution (151,152). Shimazu et al. performed simultaneous UV/visible spectroelectrochemistry and QCM (153). Optically transparent contacts to the quartz crystal were used in a transmission mode configuration. Fluorescence spectroelectrochemistry was shown to be a sensitive method for the detection of intermediates and products of electrode reactions (154,155).These authors gave details of their flow cell, which was used with a commercial luminescence spectrometer. Littig and Nieman also obtained excellent sensitivity with an electrochemical FIA chemiluminescence method (156). Electrochemical reduction of 0 2 to H202 triggered the chemiluminescence of acridinium esters in a flow cell giving a LOD in the 10-fmol range. The sophisticated fluorescence imaging of electrode surfaces cited above can also be mentioned here (E115, E295). Two simple cell designs for luminescence spectroelectrochemistry have appeared (157,158). Articles on ECL that were noted included a report that ultrasonic radiation markedly enhanced the ECL intensity in the R~(bpy)3~+/0xalate system (159)and the observation of the ECL of perylene in a room-temperature molten salt (160). A weak photoemission seen during the evolution of 0 2 a t Pt in water was assigned to the recombination of singlet oxygen molecules (161). FT-IR spectroelectrochemical studies on adsorbed C O continue to give detailed information on the interfacial structure and electrode reactions. The spectra of Roth and Weaver indicated a terminal coordination of C O over a wide potential range at Pt/nonaqueous interfaces (162).Bands in the ATR-IR spectra of CO on Pt were assigned to a linearly bonded C O and possibly a multiply bonded species (163). FT-IR spectra of CO on Ni electrodes in KOH(,,) indicated oxidation via bridge-bonded C O to generate carbonate ions (164).Cation effects on the IR spectra of C O adsorbed on
Pt were interpreted in terms of an electrochemical Stark effect in which the cation altered the position of the outer Helmholtz plane (165). Quantum mechanical X, calculations, which assumed a Pt4 cluster as a model for the electrode surface, were used to calculate the potential dependence of uco at Pt electrodes (166). C O coverages on Pt were obtained from FT-IR absorbance values after oxidation of C O to C02 in a thin-layer cell (E264). Differences were noted between the in situ and the ex situ IR reflection absorption spectra of HSO4- adsorbed on P t ( l l 1 ) (167). The in situ spectra indicated adsorption at positive potentials and a potential dependence of A,,. Adsorption of CH3CN on gold was followed by subtractively normalized FT-IR spectroscopy which gave a picture of the double layer containing two types of CH3CN and H 2 0 in the interfacial region (168). In situ FT-IR spectroelectrochemistry was performed on cobalt electrodes in NaOH(,,, (169),Si single crystal wafer electrodes (170),and Ru electrodes in aqueous acid and alkaline solutions (171). In several instances, in situ infrared spectroscopy has given information on the orientations of molecules at electrode surfaces. For example, anthraquinonedisulfonatesadopted a flat orientation initially and then a more perpendicular configuration as the adsorption proceeded (172).Polarization modulation FT-IR spectra of thick phenazine and phenothiazine films indicated that most of the molecules were oriented either perpendicular (in one case) or parallel (in two cases) to the electrode surface (173). In situ reflectance IR spectra indicated that the very narrow CV wave seen for heptylviologen on Hg was due to a faradaic reaction (174). While solution spectroelectrochemical studies have been generally omitted from this survey, attention will be called to the extensive set of data, including IR band assignments, for nine p-quinone molecules in five solvents (175). On the experimental side, a three-electrode IR optically transparent thin-layer electrochemical cell was detailed that allowed minimal diffusionof 0 2 into thecell (176).Electrodes used in ATR spectroelectrochemical cells included a gold minigrid placed on the surface of a ZnSe element (177)and a BaF2 crystal coated with a 30-nm Au layer (178).A detailed description of the problems that arise in the use of Ge or GaAs crystals for ATR spectroelectrochemistry has appeared (179). FT-IR external reflection spectroelectrochemistry has been carried out using a step-scanning, phase-modulated spectrometer and controlled-potential electrochemical modulation of the signal (180).Since Fourier frequencies due to movement of the interferometer mirror are reduced to zero in stepscanning spectrometers, cross-talk between the Fourier frequencies and modulation of the electrode potential is minimized. The feasibility of the technique was established for the surface oxidation of C O on Pt. For spectra obtained with more conventional instruments, simple trapezoidal integration of the EMIRS spectra led to improved spectra and more convincing peak assignments (181,182). In situ spectroelectrochemistry was performed using synchrotron radiation in the far-IR region, which is 1001000 times brighter than conventional black body radiation (183,184).The decomposition of C104- in an acid electrolyte
was indicated by the appearance of bands due to adsorbed chloride. Real-time surface-enhanced Raman spectroscopy (SERS) of the electrooxidation of Pt, Rh, Ru, and Au surfaces was performed using a charge-coupled device detector. Raman bands in the 250-850-cm-l region were assigned to metaloxygen vibrations; M-0 and M-OH vibrations were distinguished by the use of D20 solvent (185). SERS spectra acquired during the oxidation of C O at Au, Pt, and Rh films on gold substrates detailed the interrelations between C O and metal surface oxidation processes (186). In situ SERS of adsorbed oxygen on Ag was performed under a wide range of conditions on various supports, including YzO3-stabilized ZrO2 (187). SERS spectra were reported for oxide films at Ti and copper electrodes (188,189). Pemberton and co-workers have continued their studies of the orientation of adsorbed alcohol molecules at silver and gold electrodes (190-194). They deduced the orientations, which were generally potential dependent, from the relative intensities of the symmetric and the asymmetric C-H vibrations of the methyl and methylene groups in the adsorbates. Interestingly, their spectra indicated that the solvent structure and orientation were maintained upon emersion from butanol solvents (192). SERS of adsorbed pyridine and related molecules continues to be a popular topic. Often perpendicular, or nearly perpendicular, orientations are reported (195-197),although SERS spectra of indole on roughened Ag were interpreted in terms of a parallel orientation (198). Articles appeared on SERS of pyridine adsorption on Cu and Ag (199),the effect of Pb UPD on pyridine adsorption on Cu electrodes (1100), and 4-mercaptopyridine adsorption at mechanically polished polycrystalline Pt (1101). A SERS study of coadsorbed nicotinic acid and 3-acetylpyridine on Ag featured detailed band assignments (1102). The intensity of SERS spectra of pyridine on Ag, as activated in the usual fashion by redox cycling, was found to be related to the magnitude of the cathodic charge applied in the activation and was roughly independent of the anion (1103). In situ SERS has been used to good effect to identify intermediates and products of electrode reactions. Systems studied recently include the oxidation of diphenylamine in CH3CN (1104,the oxidation of o-aminophenol(1105,1106), the surface redox chemistry of p-mercaptoaniline (1107),the oxidation of adsorbed sulfur on gold (1108),and the oxidation of pyrite in neutral solutions (1109). SERS spectra of the 43N'+ cation radical in CH3CN were obtained in a flow cell without interference from dimeric products (1110). SERS of organic sulfides was carried out at a rotating silver electrode in order to eliminate experimental artifacts due to photoreactions (1111). Other SERS electrochemical studies included electrodeposition of Ag from a cyanide bath (1112), the Cu/CuSCN electrode (1113),and Ni electrodes in the presence of electrodeposited Ag (1114). Time-resolved SERS was impressively performed in a pulse mode at low power in order to detect intermediates of electrode reactions on the nanosecond time scale (1115). Time-resolved SERS spectra for the reduction of heptylviologen on Ag indicated the existence of nucleation phenomena at short times (1116). Analytical Chemistry, Vol. 66, No. 12, June 15, 1994
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In situ Raman spectra of Zn-phthalocyanine films on Au and glassy carbon electrodes were obtained with a confocal spectrometer. A significant aspect of this study was that the irradiated spot on the electrode surface had a diameter of less than 1 ym (1117). Simonet and co-workers have used spin traps to detect radical intermediates in the electrochemical reduction of several species (1118,11 19). For the reduction of (C6Hs)dP+ in nonaqueous solvents, it appeared that the CsH5' radical was not an intermediate. ESR was also used to follow the intercalation of lithium into V2O5 cathodes (1120). The time frame accessible in the ESR-electrochemistry experiment was ca. 1 s in the study of Dunsch and Petr (1121). 13C N M R spectra were obtained for I3C-enriched C O on Pt-black surfaces under potential control (1122). Line narrowing and chemical shifts were seen associated with changes in the CO bonding at the surface. Another original spectroelectrochemical study was the in situ determination of atomic magnetic susceptibility using a nonspinning cell that operatedin the boreof a 400-MHzNMR spectrometer (1123). The test system for this study was a 0.1 M Fe(CN)63-/4COUpk in D20 solution. Several applications of ellipsometry to electrochemistry have been described by Hamnett (1124). Ellipsometric transients were followed during adsorption of thiols on gold, growth of metal oxide films, and growth and switching of polymer films. The time scale was relatively slow, on the order of seconds, but the author predicted advances in instrumentation that would allow measurements in the millisecond range, as well as spatial resolution of ca. 10" cm2. Chao et al. measured effective dielectric constants for the electrode/solution interface at single crystal electrodes using an ellipsometry method (1125). Electrochemical quartz microbalance methodology has proved to be useful for the study of a variety of interfacial processes as evidenced by the many applications to surface electrochemistry and polymer film electrodes cited above. Several recent papers have addressed experimental artifacts that can arise with this technique. The problem of nonuniform mass sensitivity across a QCM electrode surface was treated authoritatively by Hillier and Ward (1126). Bacskai et al. have also considered the QCM response for uneven coatings of polymer films (1127). The effect of surface microstructure on the QCM response was analyzed, and the analysis applied to roughened Ag/AgCI surfaces (1128). Frequency shifts on the order of a few hertz (e20 Hz) were seen for EQCM experiments with nonadsorbing couples for 5-MHz AT-cut quartz crystals (1129). These shifts were assigned to changes in the density and viscosity of the depletion layer at the electrode surface. EQCM of poly(bithiophene) electrodes indicated that rigid films were electrodeposited from CH3CN up to 50 nmol/cm2 electroactive sites and that the Sauerbrey equation was valid (1130). For thicker films departure from rigidity was seen. The dependence of the superficial energy of a QCM oscillator on elastic strain and stress predicted by the Lippmann equation was experimentally verified (1131). By use of a dual QCM oscillator, connected to the EQCM via a pressure chamber, the effects of mass and surface energy could be separated. 410R
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A fast EQCM apparatus was used to study ion-exchange reactions of poly(pyrro1e); a resolution of a few nanograms in a measuring time of 1 ms was achieved (1132). The EQCM experiment was performed with 30-MHz AT-cut quartz crystals that had been chemically milled to produce a thin disk surrounded by a thick quartz ring (1133). The resulting high-frequency operation afforded significantly increased sensitivity.
J. INSTRUMENTATION Circuit diagrams have been published for an instrument that simultaneously measured the electrode potential and the resistance of an electrolyte solution ( J I ) and for several potentiostats (J2-J4). The single op amp potentiostat of Amatore and Lefrou allowed for ohmic drop compensation at sweep rates up to 300 kV/s. An instrument for digital ac voltammetry has also been described (J5). A Fourier transform impedance spectrometer, which operated in the frequency range 10-3-105 Hz, was described in some detail (56). Schefold gave details of an instrument for intensity-modulated photocurrent spectroscopy that employed a red LED as the light source ( J 7 ) . It was used in a nice study of charge transfer at p-InP single crystal electrodes. A simple impedance instrument was described for measurement of double-layer capacities ( J 8 ) . Several experimental apparatuses designed for operation under extreme conditions were noted. These include an automatic setup for impedance measurements on two-electrode cells over a frequency range from to lo7 Hz and a programmed temperature range from room temperature to 1100 K ( J 9 ) . Pressure effects on electrochemical potentials were measured with a cell that withstood pressures up to 10 kbar (J10). The Ag/AgCl reference electrode potential was found to be relatively pressure insensitive in this study. The high-pressure cell of Sachinidis et al. operated at pressures up to 1.5 kbar ( J I 1 ) . Cyclic voltammograms of several metal/ metal oxide couples were obtained at 700-900 OC in an yttriastabilized zirconia oxygen ion conducting electrolyte (J12). As noted above, low-temperature electrochemistry has been performed at superconducting UMEs; details of a cell design were given by Green et al. (E346). Several cleverly designed flow cells have been described including a RVC spectroelectrochemical detector for LCEC ( J 1 3 ) ,a carbon fiber cell (514, and a flow reactor containing mosaics of ion-exchange membranes and bipolar metal electrodes (J15). In the latter device, electrons and ions were transported in the same or opposite directions by the driving forces of redox potential and concentration gradients. A technique called "current spike polarography" was used to study aqueous/air interfaces and thin films of solution held in a silver ring (J16). In the latter situation, a small volume of solution (0.01 mL) was positioned just below a DME capillary and the i-E-t transients were measured as the Hg drop touched and fell through the solution. Comparison of the zero current potential with that of the bulk solution polarogram gave an estimate of the surface potential of the electrolyte solution. Reference electrodes recommended for nonaqueous solvents included the 13-/1- couple in CH3CN (J17), a cross-linked poly(ethy1eneimine) film electrode loaded with Fe(CN)63-/4
(JZ8), and Mg(Hg) amalgam in D M F (J19). An electrode, consisting of 6 Ag/AgCl wire embedded in PTFE/alumina/ KCl layers pressed into pellet form, performed nicely as a pressure-insensitivereference electrode for in situ natural water studies (J20). The standard potentials of glass electrodes with internal solutions of zwitterion buffers were reported to vary linearly with temperature over the range 5-50 OC (J2Z). Construction of a miniature, needle-type, working electrode/ reference electrode assembly, 0.5 mm in diameter, for sensing glucose was described (522). A dual-reference electrode consisting of a SCE and a Pt wire connected by a 0.1-pF capacitor was recommended on the basis of its high impedance response (523). Tieman et al. employed a three-electrode sensor made by screen printing Pt onto a ceramic substrate (J24),and a very simple procedure for sealing gold into glass using glass soldering powder was reported (J25). Experimental details were given for fitting DMEs with commercially available PTFE tips for use in media that attack glass capillaries (J26). The same group reported on a simple, automatic HDE, DME, SHDE apparatus (J27). A Hg film electrode covered by a cellulose membrane was used to quantify metal species directly on a TLC plate (J28). Several interesting descriptions of porous electrodes have appeared. The gas-sensing electrodes of Tierney and Kim had fast response times due to the absence of a semipermeable membrane and the fact that the gas molecules came directly in contact with the working electrode (J29). They used two types of porous substrates: an alumina ceramic and a micromachined silicon wafer with an array of 10-pm holes. Microporous gold films, which replicated the structure of an anodic porous alumina template, had a narrow distribution of pore diameters around a value of 100 nm (J30). Tang and Chan constructed gas diffusion electrodes by electrodeposition of Ag on commercially available Ni mesh ( J 3 1 ) . An open pore network Pt electrode was stabilized by a procedure that involved heating Pt and yttrium oxide powders at T I 1500 “ C (J32). To drive home the reoccurring observation that little is new these days, a fascinating description of a French patent granted to P. L. Hulin in 1893 for a “flow-through porous electrode” is recommended reading (J33). A technique for iR, compensation involved measurement of the ac impedance at high frequency and adjustment of the applied potential under computer control by thevalue of Id& ( J 3 4 ) . The measurement and correction routine was completed in ca. 2 ms using a 12-bit, 10-ps ADC and a 486 PC. Details of software packages for interfacing PAR 273 and 174 potentiostats have been published (535,J36). Andrieux et al. found that digital and analog filtering of CV i-E data, while decreasing random error on peak potential measurements, resulted in increased systematic error (J37). LITERATURE CITED A. BOOKS AND REVIEWS (Al) (A2) (A3) (A4) (A5) (A6)
Ryan, M. D.; Chambers, J. Q. Anal. Chem. 1992, 64, 79R-116R. Fogg, A. Analyst 1992, 177, 1801. Zuman, P. Analyst 1992, 177, 1803-1809. Eccles, 0. N. Crlt. Rev. Anal. Chem. 1991, 22,345-380. Osteryoung, J. Acc. Chem. Res. 1993, 26. 77-83. VanLeeuwen, H. P.; Buffle, J.; Lovric, M. Pure Appl. Chem. 1992, 64, 1015- 1028.
Koryta, J. Ions, Electrodes andMembranes, 2nd ed.;J. Wiley & Sons: New York, 1991. Kapoor, R. C.; Aggarwal, B. S.Principles ofPolarcQraphx Wlley: New York, 1991. Runo, J. R.; Peters, D. 0. J. Chem. Educ. 1993, 70,708-713. Gileadi, E. Electrode Klnetlcs; VCH Publlshers, Inc.: New York, 1993. Bard, A. J.; Abrub, H. D.; Chldsey, C. E.; Faulkner, L. R.; Feldberg, S. W.: Itaya, K.: MaJda,M.; Melroy. 0.; Murray, R. W.; Porter, M. D.; Sorlaga, M. P.; Whlte. H. S. J. Phys. Chem. 1993, 97,7147-7173. Bard, A. J. Pure Appl. Chem. 1992, 64. 185-192. Modem Aspects of Electrochemistry; Bockrls, J. O’M., Conway, 8. E., Whlte, R. E., Eds.; Plenum: New York, 1993; VoI. 25. Modern Aspects of Electrochemistry; Conway, B. E., Bockrls, J. O’M., Whlte, R. E., Eds.; Plenum: New York, 1992; Vol. 23. ModemAspects ofEktctroahemlstry;WMe. R. E., Conway, B. E., Bockris, J. OM., Eds.; Plenum: New York, 1993; Vol. 24. Electrochemlttyln TransitknFrom the2W, to the2 7st Centwy; Murphy, 0. J., Srlnhrasan, S.,Conway, B. E., Eds.; Plenum: New York, 1992. Advances In Electrochemlcl Sclence and Englneerlng, Gerlscher, H., Tobias, C. W., Eds.; VCH Publlshers: Welnhelm, 1992; Vol. 2. AdswptionofMoleculesatMetalElectrodes; Llpkowskl, J., Ross, P. N., Eds.; VCH, Inc.: New York, 1992. StructureofEfectrifled Interfaces;Lipkowskl, J., Ross, P. N., Eds.; VCH Publishers: New York, 1993. Comprehenslve Chemlcal Klnetlcs. Reactions at the Liquid-SolU Interface: Compton, R. G., Ed.; Elsevler: Amsterdam, 1989; Vol. 28. Electrlfied Interfaces h Physlcs, Chemism and Biology; Guldelll, R., Ed.; Kluwer Academlc Publlsher: Hlngham, MA, 1992. Weaver, M. J. Chem. Rev. 1992, 92,463-480. Galus, Z. Pure Appl. Chem. 1991, 63, 1705-1714. Saveant, J.-M. Acc. Chem. Res. 1993, 25, 455-461. Trasattl, S.Electrochim. Acta 1992, 37,2137-2144. Parsons, R.; Rltzoulls, 0. J. Electroanal. Chem. 1991. 378, 1-24. Soriaga, M. P. Frog. Surf. Sci. 1992, 39,325-443. Appleby, A. J. J. Electroanal. Chem. 1993, 357, 117-179. Bockris, J. O M ; Khan, S.U. M. Surface Electrochemishy: A Molecular Level Approach; Plenum: New York, 1993. Koelle, U. New J. Chem. 1892, 76, 157-169. Pure Appl. Chem. 1991, 63,1759-1779. Trasattl. S.;PeMi, 0. A. J. Electroanal. Chem. 1992, 327,353-376. Techniques for Characterlzatlon of Electrodes and Electrochemical Processes; Varma. R.. Selman, J. R., Eds.; Wlley: New Yofk, 1991. Christensen, P. A. Chem. Soc. Rev. 1992. 27, 197-208. Buttry, D. A.; Ward, M. D. Chem. Rev. 1992, 92, 1355-1380. Hillman, A. R.; Loveday, D. C.; Swann, M. J.; Bruckenstein, S.; Wllde, C. P. Analyst 1992, 1251-1257. Volk, K. J.; Yost, R. A.; BraJter-Toth, A. Anal. Chem. 1992, 64, 21A33A. Ashley, K. Talanta 1991, 38, 1209-1218. Rajeshwar. K.; Lema, R. 0.; de Tacconl, N. R. Anal. Chem. 1992, 64, 429A-441A. E&troana!MzdChemishy, Bard, A. J., Ed.; Marcel Dekker: New York, 1993: Vol. 18. Inzen, G. Acta Chlm. Hung. 1992, 729,365-382. Mcroekctrotlas: mory and Applications. Proceedings of NATO AdvancedSW Inst&&, A h , Portbgal,May 1426,1990; Montenego, M. I., Queiros, M. A,, Daschbach, J. L., Eds.; Kluwer Academic Publishers: Hingham, MA, 1991. Heinze, J. Angew. Chem., Int. Ed. Engl. 1993, 32, 1268-1288. MolecularDeslgnof ElectrodeSurfaces; Murray, R. W., Ed.; Techniques of Chemistry Series XXII; John Wlley & Sons: New York, 1992. Forster, R. J.; Vos, J. G. Compr. Anal. Chem. 1992, 27,465-529. Zagal, J. H. Coord. Chem. Rev. 1992, 179,89-138. Imisides, M. D.; John, R.; Riley, P. J.; Wallace, G. G. Electroanalysls 1991, 3,878-889. Labuda. J. Sel. Electrode Rev. 1992, 74, 33-86. Cox, J. A.; Jaworski, R. K.; Kulesza, P. J. Electroanalysis 1991, 3. 869-877. Electrwesponsive Mdecular 8nd Polymeric Systems; Skothelm, T. A., Ed.; Marcel Dekker, Inc.: New York, Basel and Hong Kong. 1991; Vol. 2. Mlrkln, C. A.; Ratner, M. A. I n Annual Review of Physical Chemistry; Strauss, H. L., Ed.; Annual Reviews: Palo Alto, CA, 1992; Vol. 43. McDevitt, J. T.; Riley, D. R.; Haupt, S. G. Anal. Chem. 1993, 65, 535A545A. Bruce, P. 0.; Vlncent, C. A. J. Chem. SOC.,Faraday Trans. 1993, 89, 3187-3203. Lapkowskl, M. Mater. Scl. 1991, 77,7-14. Curran, D.; Grimshaw, J.; Perera, S. D. Chem. Soc. Rev. 1991. 20, 391-404. Alvarez-Icaza, M.; Bllltewski, U. Anal. Chem. 1993, 65, 525A-533A. Heller, A. J. Phys. Chem. 1992, 96. 3579-3587. Bardelettl, 0.; Sechaud, F.; Coulet, P. R. Bloprocess Technol. 1991, 75, 7-45. Blosensws: A PractlcalApproach;Cass, A. E. 0..Ed.; Oxford Unlverslty Press: New York, 1990. Alzawa, M. Anal. Chlm. Acta 1991, 250, 249-256. Wring, S. A.; Hart, J. P. Analyst 1992, 777,1215-1229. Green, M. J. Analyst 1991, 716, 1217-1220. Hlldkch, P. I.; Ewlng. A. G.; Strein, T. 0.; Lau, Y. Y. Acc. Chem. Res. 1992, 25, 440-447. Smyth, W. F. Voltammetrlc Determination of Molecules of Biologlcal Slgnlflcance; Wiley: Chlchester, 1992. Casskfy, J. F. Compr. Anal. Chem. 1992, 27, 1-89. van den Berg, C. M. G. Anal. Chim. Acta 1991, 250, 265-276. Tur’yan, Y. I. J. Electroan81. Chem. 1992, 338, 1-30.
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Barisci, J. N.; Riley, P. J.; Wallace, G. G. Compr. Anal. Chem. 1992, 27, 71-113. Gosser, D. K., Jr. Cyclic Votfammerty: Simulation and Analysis of Reaction Mechanisms;VCH Publishers, Inc.: DeerfieldBeach, FL, 1993. Organic Electrochemistry.An Zntroduction and a GuMe, 3rd ed.; Lund, H., Ed.; Marcel Dekker: New York, 1991. Electroorganic Synthesis. Festschrlff for ManuelM. Baizec Little, R. D., Weinberg, N. L., Eds.; Marcel Dekker: New York, 1991. Shono, T. Elechoorganic Synthesls: Academic Press, Ltd.: London, 1991. Niyazymbetov, M. E.; Evans, D. H. Tetrahedron 1993, 49, 9627-9688. Silvestri, G.; Gambino, S.; Filardo, G. Acta Chem. Scand. 1991, 45, 987-992. Electrochemical and Electrocafalytic Reduction of Carbon Dioxide; Sullivan, B. P., Ed.; Elsevier: Amsterdam, 1993. Karpinets, A. P.; Bezuglyi, V. D. Elektrokhimlya 1992, 28, 638-653. Watanabe, T.; Kobayashi, M. Chlorophylls 1991, 287-315. Wayner, D. D. M.; Parker, V. D. ACC.Chem. Res. 1993, 26, 287-294. Koval, C. A.; Howard, J. N. Chem. Rev. 1992, 92, 411-433. Gratzel, M. Coord. Chem. Rev. 1991, 111, 167-174. Humphry-Baker, R.; Muller, E.; Nazeeruddin, M. K.; Kay, A.; Rodicio, I.; Liska, P.; Vlachopoulos, N.; Gratzel, M. J. Am. Chem. SOC.1993, 115, 6382-6390. Jung, K. H.; Shih, S.; Kwong, D. L. J. Electrochem. SOC. 1993, 140, 3048-3064. Brodsky, A. M. I n Excess Electrons in Dielectric Media; Ferradini, C., Jay-Gerin, J.-P., Eds.; CRC Press: Boca Raton, FL, 1991; pp 349-365. New Trends in Electrochemistry; Decker, F., Scrosati, B., Eds.; Electrochim. Acta 1993, 38, 1-157. J. Electroanal. Chem. 1993, 355, 1-20. J. Electroanal. Chem. 1993, 357, 1-46.
B. MASS TRANSPORT (BI) (82)
(B3) (84) (85) (B6) (87) (BE) (B9) (B10) (B11) (812) (813) (814) (815) (B16)
412R
Mirkin, M. V.; Bard, A. J. Anal. Chem. 1992, 64, 2293-2302. Pastore, P.; Magno, F. J. Elecfroanal. Chem. 1992, 333, Lavagnini, I.; 1-10, Fieischmann, M.; Pons, S.; Daschbach, J. J. Elechoanal. Chem. 1991, 317, 1-26. Kalapathy, U.; Tallman, D. E.; Hagen, S. J. Elecfroanal. Chem. 1992, 325, 65-8 1. Oldham, K. 8. J. Electroanal. Chem. 1992, 323, 53-76. Bender, M. A.; Stone, H. A. J. Elechoanal. Chem. 1993, 351, 29-55. Mirkin, M. V.; Bard, A. J. J. Elechoanal. Chem. 1992, 323, 1-27. Mirkln, M. V.; Bard, A. J. J. Electroanal. Chem. 1992, 323, 29-51. Brodsky, A. M.; Burlatsky, S. F.; Reinhardt, W. P. J. Electroanal. Chem. 1993, 358, 1-20. Lavagnini, I.; Pastore, P.; Magno, F.; Amatore, C. A. J. Elechoanal. Chem. 1991, 316, 37-47. Amatore, C. A.; Fosset, B. J. Electroanal. Chem. 1992, 328, 21-32. Oldham, K. B. J. Electroanal. Chem. 1992, 337, 91-126. Myland, J. C.; Oldham, K. B. J. Elechoanal. Chem. 1993, 347, 49-91. Smith, C. P.; White, H. S. Anal. Chem. 1993, 65, 3343-3353. Oldham, K. B. Anal. Chem. 1992, 64, 646-651. Che. G.: Dona. S. Electrochim. Acta 1992, 37, 2695-2699, 27012705. Zhuang, Q.; Chen, H. J. Elecfroanal. Chem. 1993, 346, 29-51, 471475. Daasbjerg, K. Acta Chem. Scand. 1993, 47, 398-402. Lavagninl, I.: Pastore, P.; Magno, F. J. Elechoanal. Chem. 1993, 358, 193-201. Che, G.; Dong, S. Electrochim. Acta 1993, 38, 1345-1349. Bard, A. J. J. Elechoanal. Chem. 1992, 331, Yang, H.; Wipf, D. 0.: 913-924. Bond, A. M.; Feldberg, S. W.; Greenhill. H. B.; Mahon, P. J.; Coiton, R.; Whyte, T. Anal. Chem. 1992, 64, 1014-1021. Mesaros, S.; Rievaj, M.; Bustin, D. Collect. Czech. Chem. Commun. 1993, 58, 281-290. Wikiel, K.; Dos Santos, M. M.; Osteryoung, J. Electrochim. Acta 1993, 38, 1555-1558. Wikiel, K.; Osteryoung, J. Electrochim. Acta 1993, 38, 2291-2296. Borkowskl, M.; Stojek, Z. Elechoanalysis (N.Y.) 1992, 4, 615-621. Wiedemann, D. J.; Kawagoe, K. T.; Kennedy, R. T.; Clolkowski, E. L.; Wightman, R. M. Anal. Chem. 1991, 63, 2965-2970. Strein, T. G.; Ewing, A. G. Anal. Chem. 1992, 64. 1368-1373. Nyholm, L.; Wikmark, G. Anal. Chim. Acta 1992, 257, 7-13. Hsueh, C. C.; Brajter-Toth, A. Anal. Chem. 1993, 65, 1570-1574. Peng, T.; Lu, H.; Liu, G.; Cao, Y. Anal. Lett. 1992, 25, 795-805. Tabei, H.; Morita. M.; Niwa, 0.; Horiuchi, T. J. Electroanai. Chem. 1992, 334, 25-33. Wollman, E. W.; Wrighton, M. S. Thh Frisbie, C. D.; Fritsch-Faules, I.; Solid Films 1992, 21Ol211, 341-347. Wang, J.; Naser, N.; Renschler, C. L. Anal. Lett. 1993,26,1333-1346. Kuhr, W. G.; Barrett, V. L.; Gagnon, M. R.; Hopper, P.; Pantano. P. Anal. Chem. 1993, 65, 617-622. Pantano, P.; Kuhr, W. G. Anal. Chem. 1993, 65,623-630. Kawagoe, J. L.: Niehaus, D. E.; Wightman, R. M. Anal. Chem. 1991, 63, 2961-2965. Strein, T. G.; Ewing, A. G. Anal. Chem. 1993, 65, 1203-1209. Lau, Y. Y.; Wong, D. K. Y.; Luo, G.; Ewing, A. G. Electroanalysis 1992, 4, 865-869. Huang, W.; McCreery, R. J. Electroanal. Chem. 1992, 326, 1-12. Wu, H. P. Anal. Chem. 1993, 65, 1643-1646. Shimizu, Y.; Morita, K. J. Electrochem. SOC.1992, 139, 1240-1243. Li, W.; Virtanen, J. A,; Penner, R. M. J. Phys. Chem. 1992, 96, 65296532.
Analytical Chemistry, Vol. 66, No. 12, June 15, 1994
Brumlik, C. J.; Martin, C. R.; Tokuda, K. Anal. Chem. 1992, 64, 12011203. Foss, C. A., Jr.; Hornyak, G. L.; Stockert. J. A,; Martin, C. R. J. Phys. Chem. 1992, 96, 7497-7499. Foss, C. A., Jr.; Tierney, M. J.; Martin, C. R. J. Phys. Chem. 1992, 96, 9001-9007. Klein, J. D.; Herrlck, R. D., 11; Palmer, D.; Sailor, M. J.; Brumiik, C. J.; Martin, C. R. Chem. Mater. 1993, 5, 902-904. Kounaves, S. P.; Deng, W. Anal. Chem. 1993, 65, 375-379. Krasinski, P.; Galus, 2. J. Elechoanal. Chem. 1993, 346, 135-146. Oldham, K. 8. J. Elechoanal. Chem. 1988, 250, I . Drew, S. M.; Wightman, R. M.; Amatore, C. A. J. Elechoanal. Chem. 1991, 317, 117-124. Cooper, J. B.; Bond, A. M.; Oldham, K. B. J. Electroanal. Chem. 1992, 331, 877-895. Lee, C.; Anson, F. C. J. Electroanal. Chem. 1992, 323, 381-389. Norton, J. D.; White, H. S. J. Elecfroanal. Chem. 1992, 325, 341-350. Cooper, J. B.; Bond, A. M. Anal. Chem. 1993, 65, 2724-2730. Norton, J. D.; Anderson, S. A.; White, H. S. J. Phys. Chem. 1992, 96, 3-6. Bento, M. F.; Medeiros, M. J.; Montenegro, M. I.; Beriot, C.; Pletcher, D. J. Elecfroanal. Chem. 1993, 345, 273-286. Ciszkowska, M.; Stojek, 2. J. Electroanal. Chem. 1993, 344, 135-143. Bard, A. J.; Garcia, E.; Kukharenko, S.; Strelets, V. V. Znorg. Chem. 1993, 32, 3528-3531. Safford. L. K.; Weaver, M. J. J. Electroanal. Chem. 1992, 331, 857876. Wooster, T. T.; Longmire, M. L.; Zhang, H.; Watanabe, M.; Murray, R. W. Anal. Chem. 1992, 64, 1132-1140. Bond, A. M.; Pfund, V. B. J. Elechoanal. Chem. 1992, 335, 281-295. Vuki, M.; Kalaji, M.; Nyholm, L.; Peter, L. M. J. Electroanal. Chem. 1992, 332, 315-323. Golas, J.; Drickamer, H. G.; Faulkner, L. R. J. Phys. Chem. 1991, 95, 10191-10197. Golas, J.; Drlckamer, H. G.; Faulkner, L. R. Acta Chim. Hung. 1992, 129, 497-518. Dressman, S. F.; Garguilo, M. G.; Sullenberger, E. F.; Michael, A. C. J. Am. Chem. SOC. 1993, 175, 7541-7542. Ciszkowska, M.; Stojek, Z.; Morris, S. E.; Osteryoung, J. G. Anal. Chem 1992, 64, 2372-2377. Morris, S . E.; Ciszkowska, M.; Osteryoung, J. G. J. Phys. Chem. 1993, 97, 10453-10457. Feinberg, J. S.;Bowyer, W. J. Mlcrochem. J. 1993, 47, 72-78. Baldo, M. A.; Danieie, A.; Mazzocchin, G. A. Anal. Chlm. Acta 1993, 272, 151-159. Daniele, S . ; Mazzocchin, G. A. Anal. Chim. Acta 1993, 273, 3-1 1. Gorski, W.; Cox, J. A. J. Elechoanal. Chem. 1992, 323, 163-178. Unwin, P. R.; Bard, A. J. Anal. Chem. 1992, 64, 113-119. Bowyer, W. J.; Clark, M. E.; Ingram, J. L. Anal. Chem. 1992, 64.459462. Bard, A. J. Anal. Chem. 1992, 64, 1362-1367. Wipf, D. 0.; Mirkin, M. V.; Fan, F.-R. F.; Bard, A. J. J. Electroanai. Chem. 1992,328, 47-62. Bard, A. J.; Mirkin, M. V.; Unwin, P. R.; Wipf, D. 0. J. Phys. Chem. 1992, 96, 1861-1868. Mirkin, M. V.; Richards, T. C.; Bard, A. J. J. Phys. Chem. 1993, 97, 7672-7677. .. - . .. . (879) Mirkin. M. V.; Buihhs, L. 0. S.; Bard, A. J. J. Am. Chem. SOC.1993, 715. 201-204. (B80) Zhou, F.; UnwhP. R.; Bard, A. J. J. Phys. Chem. 1992,96,4917-4924. (B81) Pierce, D. T.; Unwin, P. R.; Bard, A. J. Anal. Chem. 1992, 64, 17951804. (882) Horrocks, 8. R.; Mirkin, M. V.; Pierce, D. T.; Bard, A. J.; Nagy, G.: Toth. K. Anal. Chem. 1993, 65, 1213-1224. (883) Mirkin, M. V.; Arca, M.; Bard, A. J. J. Phys. Chem. 1993, 97, 1079010795. (884) Scott, E. R.; White, H. S.; Phipps, J. 8. Anal. Chem. 1993, 65, 15371545. (B85) Frank, M. H. T.; DenuauR, G. J. Electroanal. Chem. 1993, 354, 331339. (B86) Kwak, J.; Anson, F. C. Anal. Chem. 1992, 64, 250-256. (887) Mirkin, M. V.; Fan, F. R.; Bard, A. J. Science 1992, 257, 364-369. (B88) Unwin, P. R.; Bard, A. J. J. Phys. Chem. 1992, 96, 5035-5045. (889) Ciolkowski, E. L.; Cooper, B. R.; Jankowski, J. A.; Jorgenson, J. W.; Wightman, R. M. J. Am. Chem. SOC.1992, 114, 2815-2821. (B90) Schroeder. T. J.; Jankowski, J. A.; Kawagoe, K. T.; Wightman, R. M.; Lefrou, C.; Amatore, C. Anal. Chem. 1992, 64, 3077-3083. (B91) Chen, T. K.; Lau, Y. Y.: Wong, D. K. Y.; Ewing, A. G. Anal. Chem. 1992, 64, 1264-1268. (892) Lau, Y. Y.; Abe, T.; Ewing, A. G. Anal. Chem. 1992, 64, 1702-1705. (893) Tanaka, K.; Kobayashi, F.; Isogai, Y.; Iizuka, T. Bioelechochem. Bioenergetlcs 1991, 26, 413-421. (894) Matsue, T.; Koike, S.; Abe, T.; Itabashi, T.; Uchida. I.Biochim. Siophys. Acta 1992, 1101, 69-72. (895) Malinski, T.; Taha. 2. Nature 1992, 358, 676-678. (896) Renner, K. J.; Pazos, L.; Adams, R. N. Brain Res. 1992, 577, 49-56. (897) Cammack, J.; Ghasemzadeh, B.; Adams. R. N. Brah Res. 1991, 565, 17-22. (B98) Ghosh, P. M.; Keese, C. R.; Glaever. I.Blophys. J. 1993, 64, 16021609. (B99) Amatore, C.; Fosset, E.;Maness, K. M.; Wightman. R. M. Anal. Chem. 1993, 65, 2311-2316. (8100) Morita, M.; Horluchi, T.; Tabei, H. J. Electroanal. Chem. 1992, 322, 191-201. Xu, Y.; Halsall, H. B.; Hieneman, W. R. Anal. Chem. 1993, (8101) Niwa, 0.; 65, 1559-1563.
(8102) Horiuchi, T.; Niwa, 0.; Morka, M.; Tabei, H. Anal. Chem. 1992, 64, 3206-3206. (8103) Nishihara. H.; Dalton, F.; Murray, R. W. Anal. Chem. 1981, 63, 29552960. (8104) Nishizawa, M.; Sawaguchi, T.; Matsue, T.; Uchida, I.Synfh. Met. 1091, 45, 241-248. (8105) Ju, H.; Chen, H.; Gao, H. J. flectroanal. Chem. I W 2 , 347, 35-46. (8106) Peng. W.; Wang. E. Anal. Chem. Wg3, 65, 2719-2723. (8107) Peng, W.; Li, P.; Zhou. X. J. flecfroanal. Chem. 1993, 347, 1-14. (8108) Coiiinson, M. M.; Wightman. R. M. Anal. Chem. 1993,65,2576-2562. (8109) Bartelt, J. E.; Drew, S. M.;Wightman, R. M. J. fktrochem. Soc. I W 2 , 739, 70-74. (8110) Verbrugge. M. W. J. fleckochem. SOC.1892, 739, 3529-3535. (8111) Vleil, E. J. flectroanal. Chem. l g g l , 378,61-68. (8112) Verbrugge, M. W.; Baker, D. R. J. Phys. Chem. 1992, 96,4572-4560. (81 13) Bartlett, P. N.: Eastwick-Field, V. J. Chem. Soc., Faraday Trans. I W 3 , 89, 213-216. (8114) VHt, J. E.; Johnson, D. C.; Tailman, D. E. Anal. Chem. 1993, 65, 231237. (8115) Blauch, D. N.; Anson, F. C. J. Electroanal. Chem. 1989, 259, 1. (8116) Van der Linden, 8.; Vereecken, J. J. Electroanal. Chem. 1093, 356, 13-24. (8117) V k J . E.; Johnson, D. C. J. Electrochem. SOC.1992, 739, 774-778. (8118) Engelhardt, G.; Schaepers, D.; Strehbiow, H.-H. J. Electrochem. SOC. 1092. 739. 2171-2175. (8119) Engelhardt; G.; Jabs, T.; Strehblow, H.-H. J. Electrochem. SOC.1892, 739, 2176-2181. (8120) Engeihardt, G.; Jabs, T.: Schaepers, D.; Strehbiow, H. H. Acta Chim. Hung. 1992, 729, 551-556. (8121) Schwartz, D. T. J. Electrochem. SOC.1993, 740, 452-458. (8122) Deslouis, C.; Triboilet, 8. flektrokhimiya 1993, 29, 84-88. (8123) Engeiman, E. E.; Evans, D. H. J. flecffoanal. Chem. 1993, 349, 141158. (8124) Kokkinidis, G.; Hasiotis, C.; Papanastasiou, G. J. Electroanal. Chem. 1993, 350, 235-249. (8125) Chen, Y.; Zhang, H.; Wu, 8. J. Electroanel.Chem. 1992, 335,321-326. (8126) Lei, H.; Wu, 8 . ; Cha, C. J. flectroanal. Chem. 1992, 332, 257-264. (8127) Hofseth, C. S.; Chapman, T. W. J. flectrochem. SOC.1902, 739,25252529. (8128) Baislev, H.; Britz, D. Acta Chem. Scand. 1992, 46, 949-955. (8129) Mount, A. R.; Appieton, M. S.; Albery, W. J.; Clark, D.; Hahn, C. E. W. J. flectroanal. Chem. 1992, 340, 287-300. (8130) Jiang, R.; Anson, F. C. J. Phys. Chem. l W 2 , 96, 452-458. (8131) Van der Linden, 8.;De Keyzer, R.; Vereecken, J. J. flectroanal. Chem. 1993, 349, 311-324. (8132) Aibery, W. J.; Clark, D.; Drummond, H. J. J.; Coombs, A. J. M.; Young, W. K.; Hahn, C. E. W. J. flecffoanal. Chem. 1992, 340, 99-110. (8133) Compton, R. G.; Brown, C. A. J. Colloid Interface Sci. 1993, 758, 243-246. (8134) Desiouis, C.; Ezzidi, A.; Triboiiet, 8 . J. Appl. Electrochem. 1991, 27, 1081-1066. (8135) Gabrielli, C.; Huet, F.; Sahar, A.; Vaientln, 0. J. Appl. Electrochem. 1992, 22, 801-809. (8136) Janssen, L. J. J. J. Appl. Electrochem. 1982, 22, 1091-1094. (8137) Krysa, J.; Wragg, A. A. J. Appl. flectrochem. 1892, 22, 429-436. (8138) Zdunek, A. D.; Seiman, J. R. J. Electrochem. SOC.1992, 739, 25492551. (8139) Yen, S.-C.; Wang, J.-S.; Chapman, T. W. J. flectrochem. SOC.1992, 739, 2231-2238. (8140) Fisher, A. C.; Compton, R. 0.; Brett, C. M. A.; Oliveira-Brett, A. M. C. F. J. flectroanal. Chem. 1091, 378,53-59. (8141) Compton, R. G.; Fisher, A. C.; Latham, M. H.; Brett, C. M. A.; OliveiraBrett, A. M. C. F. J. Appl. Electrochem. 1092, 22, 1011-1016. (8142) Brett, C. M. A.; Oliveira Brett, A. M. C. F.; Fisher, A. C.; Compton, R. G. J. flecffoanal. Chem. 1992, 334, 57-64. (8143) Compton, R. G.; Fisher, A. C.; Latham, M. H.; Brett, C. M. A,; OiiveiraBrett, A. M. C. F. J. Phys. Chem. 1992, 96, 8363-8367. (8144) Compton, R. G.; Fisher, A. C.; Latham, M. H.; Wellington, R. G.; Brett, C. M. A.; Oliveira Brett, A. M. C. F. J. Appl. Electrochem. 1993, 23, 98-102. (8145) Compton, R. G.; Wellington, R. 0. Electroanalysis 1902, 4, 695-700. (8146) Compton, R. G.; Fisher, A. C.; Wellington, R. G.; Dobson, P. J.; Leigh, P. A. J. Phys. Chem. 1993, 97, 10410-10415. (8147) . . TaA,R.J.;Burv,P.C.:Finnin,B.C.;Reed,B.L.;Bond,A.M.J.flectroanal. Chem. 1993,-356, 25-42. (8148) Compton, R. G.; Fisher, A. C. Electroana/ysis 1992, 4, 167-182. (8149) Chen, Q.:Wang, J.; Rayson, G.; Tian, 8.; Lin, Y. Anal. Chem. l W 3 , 6 5 , 251-254. (8150) FieMen, P. R.; McCreedy, T. Anal. Chim. Acta 1993, 273, 111-121. (8151) Stojanovic, R. S.; Bond, A. M.; Butler, E. C. V. flectroanalysis 1992, 4, 453-461. (8152) Digua, K.; Kauffmann, J. N.; Ghanem, G.; Patriarche, G. J. J. Llq. Chromatogr. 1902, 75, 3295-3313. (8153) Mattusch, J.; Weisch, T.: Werner, 0.J. Prakt. Chem. lgB2.334.49-52. (8154) Cooper, 8. R.; Jankowski, J. A.; Leszczyszyn, D. J.; Wightman, R. M.; Jorgenson, J. W. Anal. Chem. 1992, 64, 691-694. (8155) Sloss, S.; Ewing, A. G. Anal. Chem. 1993, 65, 577-581. (8156) O'Shea, T. J.; Greenhagen, R. D.; Lunte, S. M.; Lunte, C. E.; Smyth, M. R.; Radzik, D. M.; Watanabe, N. J. Chromatcgr. 1992, 593, 305312. (8157) O'Shea, T. J.; Lunte, S. M. Anal. Chem. 1993. 65, 247-250. (8158) Lu, W.; Cassidy, R. M. Anal. Chem. 1993, 65, 1649-1653. (8159) Lu, W.; CassMy, R. M. Anal. Chem. 1983, 65, 2678-2881. (8160) Mahoney, L. A.; O'Dea, J.; Osteryoung, J. G. Anal. Chlm. Acta 1993, 267. 25-33.
(8161) TaA, R. J.; Bury, P.C.; Finnin, 8. C.; Reed, 8. L.; Bond, A. M. Anal. Chem. 1993. .-. -, 65. .- 3252-3257. . -. - .-. (8162) Sparks, T. C.; Geng, C. Anal. Bbchem. 1992, 205, 319-325. (8163) Aoki, A.; Matsue, T.: Uchida, I.Anal. Chem. 1092, 64, 44-49. (8164) Takahashi, M.; Mcflta, M.; Niwa, 0.; Tabei, H. J. flecffoanal. Chem. 1992, 335, 253-263. (8165) Brown,G. N.; Birks, J. W.;Kovai.C.A. Anal. Chem. 1992.64,427-434. (8166) Wang. Y.; Yeung, E. S. Anal. Chlm. Acta 1092, 266, 295-300. (8167) Barisci, J. N.; Wallace, G. G. J. flecffoanal. Chem. 1892, 328, 195208. (8168) . . Dohertv, A. P.; Forster, R. J.; Smyth, M. R.; Vos. J. G. Anal. Chem. 1992, 64, 572-575. (8169) Malone, 1259-1 263. M. M.; Dohem, A. P.; Smyth, M. R.; Vos, J. 0. Analyst 1992, .-- - .- - -. (8170) Wang, J.; Wu, H.; Angnes, L. Anal. Chem. Wg3, 65, 1893-1696. (8171) Qalal, A.; AM, N. F.: Rubinson, J. F.; Zimmer, H.; Mark, H. 8.. Jr. Anal. Lett 1993, 26, 1361-1381. (8172) Wang. E.; Liu, A. Anal. Chlm. Acta 1091, 252, 53-57. (8173) Vandeberg, P. J.; Johnson, D. C. Anal. Chem. 1993, 65, 2713-2716. (8174) McLaughlin, L. G.; Henlon, J. D. J. Chromatogr. 1092, 59, 195-206. (8175) Wagner, H. P.; McGarrity, M. J. J. Am. Soc. Brew. Chem. 1992. 50, 1-3. (8176) . . Martens. D. A.: Frankenberaer,W. T., Jr. J. Lia. Chromatwra~hy1992. 75, 423-439. (8177) LaCourse. W. R.; Johnson, D. C. Anal. Chem. l W 3 , 65, 50-55. (8178) Vandeberg, P. J.; Kowagoe, J. L.; Johnson, D. C. Anal. Chlm. Acta . . 1982, 266, 1-11. (8179) Soucaze-Gulllous, 8.: Kutner, W.; Kadish, K. M. Anal. Chem. 1993, 65, 869-672. - - - - . -. (8180) Luo, P.; Baldwin. R. P. Electroanalysis 1992, 4. 393-401. (8161) Salto, H.; Mural, S.: Abe, E.; Masuda, Y.; Itoh, T. Pharmacol.Biochem. Behav. l W 2 , 42, 351-356. (8182) Zhu, C.; Curran, D. J. Electroanalysis WPl, 3, 511-518. (8183) Lu, J.; Tian, C. J. Elecfroanal. Chem. 1993, 345, 27-42.
.
C. ANALYTICAL VOLTAMMETRY Barker. G. C.; Jenkins, I . L. Analyst 1992, 777, R1-R11. Barker, 0.C.; Gardner, A. W. Analyst 1992, 777. 1811-1828. (C3) Chin, K. Y.; Prasad, S.; O'Dea, J. J.; Osteryoung, J. Anal. Chim. Acta 1992, 264, 197-204. (C4) Lovric, M.; Pizeta, I.; Komorskylovric, S. flecfroanalysis 1892, 4, 327-337. (C5) . . Komorskvlovric, S.; Lovric. M.; Branica. M. J. Electroanel. Cham. 1992. 335, 29f-308. (C6) Kounaves, S. P. Anal. Chem. 1992, 64, 2998-3003. Brainina, K. 2.; Viichinskaya, E. A.; Khanina, R. M.; Kalnishevskaya,L. (C7) N. flectroanalyss I W 2 , 4, 549-554. (C8) Jin, W. R.; Hou, Y.C.; Yan, C. T.; Wang, J. Y.; Sun, C. L. Electroanalysis 1992. 233-237. .- - -, 4. ., - .. Li, C. A.; James, 8. D.; Magee, R. J. Electroanalysis 1992,4, 585-587. Puy, J.; Mas, F.; DlazCrur, J. M.; Esteban, M.; Casassas, E. Anal. Chlm. Acta 1982, 268, 261-274. Mas, F.; Puy, J.; DiazCruz, J. M.;Esteban, M.; Casassas, E. Anal. Chlm. Acta 1993, 273, 297-304. Puy, J.; Salvador, J.; Galceran, J.; Esteban, M.; Diaz-Cruz, J. M.; Mas, F. J. flectroanal. Chem. 1993. 360, 1-25. Jin. W. R.; Cui, H.; Wang, S. R. Anal. Chim. Acta 1992, 268,301-306. Sugawara, K.; Tanaka, S.; Taga, M. Fresenius J. Anal. Chem. 1892. 342, 65-69. Aleixo. L. M.; Souza, M. D. 8.;Gcdinho, 0. E. S.; Neto, G. D.; Gushikem, Y.; Moreira, J. C. Anal. Chim. Acta I W 3 , 277, 143-148. Cai, X.; Kaicher. K.; Diewakl, W.; NeuhoM, C.; Magee, R. J. Fresenius J. Anal. Chem. 1993. 345, 25-31. Diewald, W.; Kalcher, K.; Neuhold, C.; Cai, X.; Magee, R. J. Anal. Chim. Acta 1993, 273, 237-244. Paniagua, A. R.; Vazquez, M. D.; Tascon, M. L.; Batanero, P. S. Electroanalysis 1993, 5, 155-163. Peng, T. 2.; Li, H. P.; Wang, S. W. Analyst l W 3 , 778, 1321-1324. Cai. X. H.: Kalcher, K.: Neuhoid. C.; Diewald. W.: Magee, R. J. Analvst l W 3 , 778, 53-57. Egashira, N.; Iwanaga, H.; Okabe, K.; Ohga, K. Anal. Sci. 1882, 8,
(C1) (C2)
. -- . - ..
71-15-707
.
.
Ramos, J. A.; Bermejo, E.; Zapardiei, A.; Perez, J. A.; Hernandez, L. Anal. Chlm. Acta 1993, 273, 219-227. Aivarez, E.; Sevilla, M. T.; Piniila, J. M.; Hernandez, L. Anal. Chlm. Acta 1992, 260. 19-23. Macias, J. M. P.; Hernandez, L. H.; Sobrino, J. M. M.; Escribano, M. T. S. Electfoanalysls 1993, 5, 79-63. Barrio. R. J.: Debaluaera. 2 . G.: Goicolea. M. A. Anal. Chim. Acta 1993. 273, 93-99. Hernandez, P.; Garcia, S.; Hernandez, L. Anal. Chlm. Acta 1992, 259, 325-331. Efstathiou, C. E. Analyst 1902. 777, 1329-1334. Cookeas. E. 0.; Liu, K. 2.; Wu, Q. G. flecfroanalysls 1992, 4, 569-573. Gorski, W.; Cox, J. A. Anal. Chem. 1992, 64, 2706-2710. Mandler, D. Anal. Chem. 1893, 65, 2089-2092. Turyan, I.; Sun. c. G.: Wana, J. Y.; Hu, W.; Xie. T. Y.; Jin, W. R. Anal. Chim. Acta 1992, 259, 319-323. Zhao, J. 2.;Sun, D. 2.; Jin, W. R. Anal. Chim. Acta 1092,268,293-299. Wang, J.; Lu, J. M.; Setiadjl, R. Tabnta 1903, 40, 351-354. Wang, J.; Setiadji, R. Anal. Chlm. Acta 1982, 264, 205-211. Farias. P. A. M.: Takase. I. flectroanalvsis W92. 4. 823-828. Stryjewska, E.; Rubel. S.fKusmierczyk, U.Chem. Anal. 1992, 37,4349.
-
Analytical Chemistry, Vol. 66, No. 12, June 15, 1994
413R
Ertas, F. N.; Fogg, A. G.; Moreira, J. C.; Barek, J. Talanta 1993, 40, I .AR .- 1. l.4 .R-R- . Fogg, A. G.; Ertas, F. N.; Moreira, J. C.; Barek, J. Anal. Chim. Acta 1993. 278.41-51. Quentel, F.'; Elleouet, C.; Madec, C. Electroanalysis 1992, 4,707-71 1. Viliar, J. C. C ; Garcia, A. C.; Blanco, P. T Anal. Chim. Acta 1992, 256, 23 1-236. Debozo, J. A.; Garcia, A. C.; Ordieres, A. J. M.; Blanco, P. T. €lectroanalysis 1992, 4, 87-92. Malone, M. A.; Garcia, A. C.; Blanco, P. T.; Smyth, M. R. Analyst 1993, 118. . , 649-655. . . ... Deipozo, J. A.; Garcia, A. C.; Blanco, P. T. Anal. Chim. Acta 1993, 273, 101-109. Bermejo,E.; Zapardiel, A,; Perez, J. A.; Huerta. A,; Hernandez, L. Talanta 1993, 40,1649-1656. ARlnoz, S.;Ozer, D.; Temizer, A,; Bayraktar, Y. Anal. Lett. 1992, 25, 111-118. Wang. 2. H.; Zhou, H. X.; Zhou, S. P. Talanta 1993, 40, 1073-1075. Peng, T. 2.; Li, H. P.; Lu, R. S. Electroanalysis 1993, 5, 177-181. Hu, S. S.;Chen, 2. L.; Zhang, T. Fresenius J. Anal. Chem. 1993, 346, 1008- 10 10. Villamii, M. J. F.; Ordieres, A. J. M.; Garcia, A. C.; Blanco, P. T. Anal. Chim. Acta 1993, 273,377-382. Economou, A.; Fielden, P. R. Analyst 1993, 778,47-51. Economou, A.; Fielden, P. R. Analyst 1993, 778, 1399-1404. Komorsky-Lovric, S.; Lovric, M.; Bond, A. M. Anal. Chim. Acta 1992, 258,299-305. Schoiz, F.; Rabi, F.; Muller, W. D. €lectroanalysis 1992, 4, 339-346. Lange, B.; Scholz, F.; Bautsch. H. J.; Damaschun, F.; Wappier, G. Phys. Chem. Miner. 1993, 79,486-491. Zhi. W.; Galai, A.; Zimmer, H.; Mark, H. 8. Electroanalysis 1992, 4, 77-85. Wallace, G.G.; Imisides, M. D. Electroanalysis 1992, 4,97-105. Wang, J.; Brennsteiner, A,; Angnes, L.; Sylwester, A,; Lagasse, R. R.; Bitsch, N. Anal. Chem. 1992, 64, 151-155. Wang, J.; Angnes, L.; Tobias, H.; Roesner, R. A,; Hong, K. C.; Glass, R. S.:Kong, F. M.; Pekala, R. W. Anal. Chem. 1993, 65,2300-2303. Wang, J.; Tian, B. M. Anal. Chem. 1992, 64,1706-1709. Frenzel, W. Anal. Chim. Acta 1993, 273, 123-137. Peng, J. X.; Jin, W. R. Anal. Chim. Acta 1992, 264,213-219. Rievaj, M.; Bustin, D. Analyst 1992, 777,1471-1472. Rievaj, M.; Mesaros, S.; Bustin, D. An. Quim. 1993, 89,347-350. Rievaj, M.; Mesaros, S.; Bustin, D. Chem. Pap-Chem. Zvesti. 1993, 47, 31-33. McLaughlin, K.; Boyd, D.; Hua, C.; Smyth, M. R. Electroanalysis 1992, 4,689-693. Nyholm, L.; Wikmark, G. Anal. Chim. Acta 1993, 273,41-51. Daniele. S.;Mazzocchin, G. A. Anal. Chim. Acta 1993, 273,3-1 1, Kounaves, S. P.; Deng, W. Anal. Chem. 1993, 65,375-379. Opydo, J. Talanta 1992, 39, 229-234. Cofre, P.;Brinck, K. Talanfa 1992, 39, 127-136. Opydo, J. Anal. Chim. Acta 1992, 262, 117-122. Barisci, J. N.; Wallace, G. G. Electroanalysis 1992, 4,323-326. Daniel, L. Y.; Zakharova, E. A,; Goloskokova, N. B.; Shelkovnikov, V. V. Zh. Anal. Khim. 1992, 47,448-455. Fernando, A. R.; Plambeck, J. A. Analyst 1992, 7 77,39-42. Diaz-Cruz, J. M.; Esteban, M.; van den Hoop, M. A. G. T.; van Leeuwen, H. P. Anal. Chem. 1992, 64,1769-1776. Saito, S.;Osteryoung, J. Anal. Chim. Acta 1992, 258,289-297. Peng, T. H.; Li, H. P.; Lu, R. S. Anal. Chim. Acta 1992, 257, 15-19. Mikac, N.; Branica, M. Anal. Chim. Acta 1992, 264,249-258. Voulgaropoulos, A.; Tzivanakis, N. Electroanalysis 1992, 4, 647-65 1. Wong, G. T. F.; Zhang, L. S. Talanta 1992, 39,355-360. Vonwandruszka, R.; Yuan, X.; Morra, M. J. Talanta 1993, 40, 37-42. Wang, J.; Lu, J. M. Anal. Chim. Acta 1993, 274,219-224. McLaughlin, K.; Rodriguez, J. R . B.; Garcia, A. C.; Blanco, P. T.; Smyth, M. R. Electroanalysis 1993, 5,455-460. 1. Smyth, W. F.; Jan, M. R. Fresenius J. Anal. Chem. 1993,346,947-95 Kotoucek, M.; Vasicova, J.; Ruzicka, J. Mlkrochim. Acta 1993, 7 7 7 , 55-62. Jin, W. R.: Zhao, X.; Du, Q.L.; Wana F. N.; Gao, 2. Q.Anal. Lett. 1992, 25,2209-2223. Ciszewski, A.; Wang, J. Analyst 1992, 777,985-988. Zanoni, M. V. B.; Fogg, A. G. Analyst 1993, 778, 1163-1166. Legall, A. C.; van den Berg, C. M. G. Analysf 1993, 778,1411-1415. Kuver. A.: Vielstich., W.:. Kltzelmann. D. J. Electroanal. Chem. 1993. 353,255-263.~ Wang, J.; Tian, B. Anal. Chem. 1993, 65,1529-1532. Zie, Y . Q.; Huber, C. 0. Anal. Chim. Acta 1992, 263,63-70. Ostapczuk, P. Clin. Chem. 1992, 38, 1995-2001. Jagner, D.; Sahlin, E.; Axelsson. B.; Ratanaohpas, R. Anal. Chim. Acta 1993, 278,237-242. Zhang, Y. L.; Jiao, K.; Liu, C. F.; Liu, X. B.Anal. Chim. Acta 1993, 282, 125-132. Komorsky-Lovric, S.;Branica, M. Anal. Chim. Acta 1993, 276,361366. Aldstadt, J. H.; Dewald, H. D. Anal. Chem. 1993, 65,922-926. Wang, J.; Lu, J. M.; Olsen, K. Analyst 1992, 777,1913-1917. Jiao, K.; Jin, W.; Metzner. H. Anal. Chim. Acta 1992, 260,35-43. Setiadji, R.; Wang, J.; Santanarios, G. Talanta 1993, 40,845-849. Wang, J.; Lu, J. M.; Taha. 2. Analyst 1992, 177,35-37. Yokoi, K.; van den Berg, C. M. G. Anal. Chim. Acta 1992, 257,293299. Yokoi, K.; van den Berg, C. M. G. Electroanalysis 1992, 4. 65-69. Bobrowski, A.; Bond, A. M. Electroanalysis 1992, 4, 975-979. Hsieh, A. K.; Ong, T. H. Anal. Chim. Acta 1992, 256,237-241.
414R
Analytical Chemistry, Voi. 66, No. 12, June 15, 1994
(C106) Jiang, 2. L.; Qin, H. C.; Wu, D. Q. Talanra 1992, 39, 1239-1244. (C107) Chan, W. H.; Lee, A. W. M.; Cai, P. X . Analyst 1992, 777,185-188. (C108) Chan, W. H.; Lee, A. W. M.; Cal, P. X. Analyst1992. 777,1509-1512. (C109) Chan, W. H.; Lee, A. W. M.; Ng, S. L.; Liu, W. L. Analyst 1992, 777, 1909-19 12. (CllO) Shiu, K. K.; Chan. W. H.; Lee, A. W.; Wong, W. C. Analyst 1993, 778, 869-872. (C111) Rodrigues, J. A.; Barros, A. A. Anal. Chim. Acta 1993, 273,531-537. (C112) Barros, A. A.; Rodrigues, J. A.; Almeida, P. J. Anal. Chim. Acta 1993, 273,539-543. (C113) Somer, G.; Kocak, A. Analyst 1993, 778,657-659. (C114) Harbin, A. M.; van den Berg, C. M. G. Anal. Chem. 1993, 65,34113416. (C115) Lyle, S. J.; Yassin, S. S. Anal. Chim. Acta 1993, 274,225-230. (C116) Reviejo, A. J.; Sampron. A.; Pingarron, J. M.; Polo, L. M. Elechosnalysis 1992. 4. , 111-120. (C117) Reviejo, A. J.; &nzalez, A,; Pingarron, J. M.; Polo, L. M. Anal. Chim. Acta 1992. 264. 141-147. ( C l l 8 ) Gaivez, R.: Pedrero, M.; Devillena, F. J. M.; Pingarron, J. M.; Polo, L. M. Anal. Chim. Acta 1993, 273,343-349. (C119) Acuna, J. A.; de la Fuente, C.; Vazquez, M. D.; Tascon, M. L.; SanchezBatanero, P. Talanta 1993, 40, 1637-1642. (C120) Garcia-Antbn, J.; Grima, R. Fresenius J. Anal. Chem. 1992, 343,905906. (C121) Ciszkowska. M.; Stojek. 2.; Morris, S. E.; Osteryoung, J. G. Anal. Chem. 1992, 64,2372-2377. (C122) Morris, S. E.; Ciszkowska, M.; Osteryoung. J. G. J. Phys. Chem. 1993, 97. 10453-10457 . ... . . (C123) Baido, M. A.; Daniele, S.;Mazzocchin, G. A. Anal. Chim. Acta 1993, 272. 151-159. ~. (C124) Perdicakis, M.; Piatnicki, C.; Sadik, M.; Pasturaud, R.; Benzakour, B.; Bessiere, J. Anal. Chim. Acta 1993, 273,81-91. (C125) Kuiesza, P. J.; Faulkner, L. R. J. Am. Chem. Soc. 1993, 775,1187811884. (C126) Batina, N.; Ciglenecki. I.; Cosovic, B. Anal. Chlm. Acta 1992, 267, 157- 164. (C127) Diaz, T. G.; Cabaniilas, A. G.; Martinez, L. L.; Salinas, F. Anal. Chlm. Acta 1993, 273,351-359. (C128) Sturm, J. C.; Nunezvergara. L. J.; Squella, J. A. Talanta 1992, 39, 1149-1 154. (C129) Corbini, G.;Biondi, C.; Proietti, D.; Dreassi, E.; Corti, P. Analyst 1993, 718,183-187. ((2130) Szczepaniak, W.; Ren, M. Anal. Chim. Acta 1993, 273,335-338. (C131) Szczepaniak, W.; Ren, M. Anal. Chim. Acta 1993, 273,339-342. (C132) Boutakhrit, K.: Elkasmi. A.; Kauffmann, J. M.; Deltour, R.; Mehbod, M.; Marvin, C. A. Electroanalysis 1993, 5,877-882. (C133) Lafage, B.; Taxil, P. J. Electrochem. Soc. 1993, 740,3089-3093. (C134) Rammohan, V.; Yadav, R. B.; Ramamurty, C. K.; Syamsundar, S. Anal. Chim. Acta 1992, 264, 149-152. (C135) Dempsey, E.; Smyth. M. R.; Richardson, D. H. S. Analyst 1992, 777, 1467-1470. (C136) Ni, Y. N.; Selby, M.; Kokot, S.; Hodgkinson, M. Analyst 1993, 778, 1049-1053. ('2137) Matysik, F. M.; Nagy, G.; Pungor, E. Anal. Chim. Acta 1992, 264,177184. - . (C138) Engbiom, S.; Bobacka, J.; Ivaska, A.; Nagy. G.; Sarkany, P.; Pungor, E. Talanta 1992, 39,819-824. (C139) Dos Santos, M. M. C.; Goncalves, M. L. S. Electrochim. Acta 1992, 37, 14 13- 1416. (C140) Wikiel, K.; dos Santos, M. M.; Osteryoung, J. Electrochim. Acta 1993, 38, 1555-1558. (C141) Iyer, V. N.; Sarin, R. Anal. Lett 1992, 25, 1915-1927. (C142) Bianchi, A.; Domenech, A.; Garcia Espana, E.; Luis, S. V. Anal. Chem. 1993, 65,3137-3142. (C143) Esteban, M.; Diaz-Cruz, J. M. Anal. Chim. Acta 1993, 287,271-280. (C144) Zelic, M.; Branica, M. Anal. Chim. Acta 1992, 268,275-284. (C145) Van den Berg, C. M. G.; Donat, J. R. Anal. Chim. Acta 1992, 257, 281-291. (C146) Van den Berg, C. M. G. Analyst 1992, 777,589-593. (C147) Navratiiova, 2.; Kula, P. Anal. Chim. Acta 1993, 273,305-311. (C148) Chakrabarti. C. L.; Lu, Y. J.; Cheng, J. G.; Back, M. H.; Schroeder, W. H. Anal. Chim. Acta 1993, 276,47-64. (C149) Agraz, R.; Sevilla, M. T.; Hernandez, L. Anal. Chim. Acta 1993, 283, 650-656. (C150) Scarano. G.;Bramanti, E.; Zirlno, A. Anal. Chim. Acta 1992, 264,153162. (C151) Fukushima, M.; Hasebe, K.; Taga, M. Anal. Chim. Acta 1992, 270, 153-159. (C152) Allus, M. A.; Brereton, R. G. Analyst 1992, 777,1075-1084. (C153) Ni. Y. N.; Kokot, S.; Selby, M.; Hodgkinson, M. Electroanalysis 1992, 4, 713-718. (C154) Esteban, M.; Ruisanchez, 1.; Larrechi, M. S.; Rius, F. X. Anal. Chim. Acta 1992, 268,95-105. (C155) Esteban. M.; Ruisanchez, I.; Larrechi, M. S.; Rius, F. X. Anal. Chim. Acta 1992, 268, 107-114. ~
~
D. HETEROGENEOUS/HOMOGENEOUS KINETICS
(Dl) (D2) (D3) (D4) (05)
Fawcett, W. R.; Opallo, M. J. Phys. Chem. 1992, 96,2920-2924. Fawcett, W. R.; Opallo, M. J. Electroanal. Chem. 1993, 349,273-284. Phelps, D. K.; Ramm, M. T.; Wang. Y .; Nelsen, S. F.; Weaver, M. J. J. Phys. Chem. 1993, 97,181-188. Fawcett. W. R.; Fedurco, M. J. Phys. Chem. 1993, 97,7075-7080. Fawcett, W. R.; Fedurco, M.; Opallo, M. J. Phys. Chem. 1992, 96, 9959-9964.
Cruanes, M. T.; Drickamer, H. G.; Fauikner, L. R. J. Phys. Chem. 1992, 96, 9888-9892. Fawcett, W. R.; Opailo, M.; Fedurco, M.; Lee, J. W. J. Electroanel. Chem. 1993, 344, 375-381. McDermott, C. A.; Kneten, K. R.; McCreery, R. L. J. Electrochem. SOC. 1993, 740, 2593-2599. Straus, J. 6.; Voth, 0. A. J. Phys. Chem. 1993, 97, 7388-7391. Berhan, J.; Geilardo, I.; Moreno, M.; Saveant, J. M. J. Am. Chem. SOC. 1992, 7 74. 9576-9583. Saveant, J. M. J. Am. Chem. SOC.1992, 774, 10595-10602. Andrieux, C. P.; Legorande, A.; Saveant. J. M. J. Am. Chem. Soc. 1992. 7 74. 6892-6904. Jaworski,J. S.; Leszczynski,P.; Kaiinowski. M. K. J. Electroanal. Chem. 1993, 358, 203-219. Cariln, R. T.; Sullivan, T.; Sherman, J. W.; Aspinwali, C. A. Electrochim. Acta 1993, 38, 927-934. Karpinski, 2. J.; Osteryoung, R. A. J. Elechoanal. Chem. 1993, 349, 285-297. Safford, L. K.; Weaver, M. J. J. Electroanal. Chem. 1992, 337, 857876. Lavagnlni, 1.; Pastore, P.; Magno, F. J. Electroanal. Chem. 1992, 333, 1-10. Birke, R. L.; Huang, 2 . P. Anal. Chem. 1992, 64, 1513-1520. Mirkln. M. V.; Bard, A. J. Anal. Chem. 1992, 64, 2293-2302. Klm, M. H.; Smkh, V. P.; Hong, T. K. J. Electrochem. SOC.1993, 740, 712-721. Munoz, E.; Rodriguez Amaro, R.; Camacho, L.; Lopez, V. J. Electroanal. Chem. 1992, 333, 153-164. Engstrom, R. C.; Small, B.; Kattan, L. Anal. Chem. 1992,134,241-244, Cassldy, J.; Breen. W.; McGee, A.; McCormacx, T.; Lyons, M. E. G. J. Electroanel. Chem. 1992, 333, 313-318. Mirkin, M. V.; Rlchards, T. C.; Bard, A. J. J. Phys. Chem. 1993, 97,
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7673-7677
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.
(D54) (D55) (D56) (D57) (D58) (D59) (D60) (D61) . . (D62) (D63) (D64) (D65) (D66) (D67)
Andrieux, C. P.; Delgado, G.; Saveant, J. M.; Su, K. B. J. Electroanel. Chem. 1993, 348, 107-121. Smith, C. P.; White, H. S.Anal. Chem. 1993, 65, 3343-3353. Eichhorn, E.; Rieker, A.; Spelser, B. Anal. Chlm. Acta 1992, 256, 243249. Hsueh, C. C.; Brajter-Toth, A. Anal. Chem. 1993, 85, 1570-1575. Bieniasz, L. K. J. Electroanel. Chem. 1993, 360, 119-138. Horno, J.; Garcla Hernandez, M. T.; Gonzaiez Fernandez, C. F. J. Electroanal. Chem. 1993, 352, 83-97. Rudolph, M.. J. Electroanal. Chem. 1992, 338, 85-98. Brltz, D. J. Electroanal. Chem. 1993, 352, 17-28. Storzbach, M.; Helnze, J. J. Electroanal. Chem. 1993, 346, 1-27. Bieniasz, L. K.; Britz, D. Anal. Chim. Acta 1993. 278, 59-70. BbniaSZ, L. K.; Britz, D. Acta Chem. Scand. 1993, 47, 757-767. Bieniasz, L. K. J. Elechoanal. Chem. 1993, 345, 13-25. Mirkin. M. V.; Bard, A. J. J. Electroanal. Chem. 1992, 323, 1-27. Mirkin, M. V.; Bard, A. J. J. Electroanal. Chem. 1992, 323. 29-51. Zhou, F. M.; Unwin, P. R.; Bard, A. J. J. Phys. Chem. 1992, 96, 49174924. Dong, S. J.; Che, G. L. Electrochim. Acta 1992, 37, 2587-2589. Che, 0. L.; Dong, S. J. Electrochim. Acta 1992, 37, 2695-2699. Che, 0. L.; Dong, S. J. Electrochlm. Acts 1992, 37, 2701-2705. Lavagnini, I.; Pastore, P.; Magno. F. J. Electroanal. Chem. 1993, 358, 193-201. Evans, D. H. J. Electroanal. Chem. 1992, 324, 387-395. Andrieux, C. P.; Haplot. P.; Saveant, J. M. J. Electroanel. Chem. 1993, 349, 299-309. Maestre, M. S.;Munoz, E.; Avila, J. L.; Camacho, L. Electrochim. Act8 1992, 37, 1129-1 134. Meiiado, J. M. R.; Montoya, M. R.; Gaivin, R. M. Electroanalysis 1992. 4, 217-221. Laviron, E.; Meunier-Prest, R. J. Electroanal. Chem. 1992, 324, 1-18. Vincent, M. L.; Peters, D. G. J. Electroanel. Chem. 1993, 344, 25-44. Kumar, V. T.; Blrke, R. L. Anal. Chem. 1993, 65, 2428-2436. Bieniasz, L. K. Comput. Chem. 1993, 77, 355-368. Bbniasz, L. K. J. Electroanal. Chem. 1992, 340, 19-34. Palvs. M. J.: 60s. M.; van der Linden, W. E. Anal. Chlm. Acta 1993,283, 81 i-829. Compton, R. G.; Wellington, R. G. Electroanalysis 1992, 4, 695-700. Fisher, A. C.; Compton, R. G. Electroanalysis 1992, 4, 311-315. Compton, R. G.; Fisher, A. C.; Spackman, R. A. Electroanalysls 1992, 4, 167-182. Compton, R. G.; Fisher, A. C.; Latham, M. H.; Wellington, R. G.; Brett, C. M. A.; Brett, A. M. C. F. 0. J. Appl. Electrochem. 1993,23,98-102. Benderskii, Y. V.; Malranovskii, V. 0. Elektrokhimlye 1992, 28, 835841. Daasbjerg, K. Acta Chem. Scad. 1993. 47, 398-402. Murphy, W. D.; Manzanares, J. A.; Mafe, S.; Relss, H. J. Phys. Chem. 1992, 96, 9983-9991, Karasevskii.A. I.: Krls. R. E.: Panov, E. V.: Gorodvskii. A. V. J. Electrasnal. Chem. 1992. 325, 45-63. Damaskin, 8. 6.; Safonov, V. A. J. Electroanel. Chem. 1992, 329, 139-1 58. IzotOviV. Y.; Kuznetsov, A. M. Elektfokhlmly8 1992,28, 1109-1117. Hsu, J. P.; KUO,Y. C. J. Chem. Soc., Faraday Trans. 1993. 89, 12291233. Daghetti, A.; Romeo, S.; Usueiii. M.; Trasatti, S. J. Chem. Soc., Faraday Trans. 1993, 89, 187-193. Hamelin, A.; Foresti, M. L.; Guidelii, R. J. Electroanal. Chem. 1993,346, 251-259. Fawcett, W. R.; Rocha, R. C. J. Chem. Soc., Faraday Trans. 1992, 86, 1143-1 148.
(D68) . . Fawcett, W. R.; Kovacova, 2.; Motheo. A. J.; Foss, C. A. J. Electroanal. Chem. 1992, 326, 91-103. (D69) Wandlowski, T.; DeLevie, R. J. Electroanel. Chem. 1992, 329, 103127. Wandlowski, T.; DeLevie, R. J. Electroanal. Chem. 1993, 345, 413432. Wandlowski, T.; DeLevie, R. J. Electroanal. Chem. 1993, 352, 279294. Swietiow, A.; Skoog, M.; Johansson, 0. Electroana&sls 1992,4,921928. Conway, B. E.; Liu, J. 6.; Qian, S.Y. J. Electroanel. Chem. 1992, 329. 201-223. Bagotskaya, I . A.; Kazarlnov, V. E. J. Electroanal.Chem. 1992, 329, 225-236. Perez, M.; Barrera. M.; Andreu, R.; Moiero, M. J. Electroanal. Chem. 1993, 367,239-249. Bai, L.; Gao, L.; Conway, B. E. J. Chem. SOC.,Faraday Trans. 1993. 89, 235-242. Jaworski, R. K.; McCreery, R. L. J. Electrochem. Soc.1993, 740,13601365. Halsey, T. C.; Leibig, M. Ann. Phys. (MY.) 1992, 279, 109-147. Leibig, M.; Halsey, T. C. Electrochim. Acta 1993, 38, 1985-1988. Unwin, P. R.; Bard, A. J. Anal. Chem. 1992, 64, 113-119. Unwin. P. R.; Bard, A. J. J. Phys. Chem. 1992, 96, 5035-5045. Papadopoulos. N.; Sotiropoulos, S.;Nikitas. P. J. Electroanal. Chem. 1992. 324, 375-385. Gu,P.; Bai, L.; Gao, L.; Brousseau, R.; Conway, B. E. Electrochlm.Acta 1992, 37, 2145-2154. Blankenborg, S. G. J.; Sluyters-Rehbach, M.; Sluyters, J. H. J. Electroanal. Chem. 1993, 349, 255-272. Avaca, L. A.; Kaufmann, S.; Kontturi, K.; Mwtomaki, L.; Schlffrin, D. J. Ber. Bunsenges. Phys. Chem. 1993, 97, 70-76. Tilak, B. V.; Conway, B. E. Electrochim. Acta 1992, 37, 51-61. Song, S. Y.; Jin, W. R.; Wang, S. R.; He, P. X. J. Electroanel. Chem. 1992. 338. ...- -, 61-72. .. . -. (D88) Jin, W. R.; Song, S.Y.; Wang, S. R.; He, P. X. J. Electroanel. Chem. 1992, 338, 73-84. (D89) Jin. W. R.; Cui. H.; Zhu, L. X.; Wang, S.R. J. Elechoanal. Chem. 1992, 340. 315-324. (D90) O'Dea, J. J.; Ribes, A.; Osteryoung, J. G. J. Electroanal. Chem. 1993, 345, 287-30 1. (D91) ODea, J. J.; Osteryoung, J. G. Anal. Chem. 1993, 65. 3090-3097. (D92) Rouquette Sanchez, S.; Picard, G. Electrochim. Acta 1993, 38, 487493. (D93) McDermott. M. T.; Kneten, K.; McCreew, R. L. J. Phys. Chem. 1992, 96, 3124-3130. (D94) Engelman, E. E.;Evans, D. H. J. Electroanal. Chem. 1992, 337, 739749 (D95) Schulz, C.; Speiser, 8. J. Electroanel. Chem. 1993, 354, 255-271. (D96) Lukaszewski, 2.; Tomaszewski, K.; Mendyk, W. J. Electroanel. Chem. 1993, 344, 13-24. (D97) Freund, M. S.;Brajter-Toth, A. J. Phys. Chem. 1992, 96, 9400-9406. (D98) Dana, S.M.; Jablonski, M. E.; Anderson, M. R. Anal. Chem. 1993, 65, 1120-1 122.
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Leiva, E. P. M. Chem. Phys. Lett. 1991, 787, 143-148. Trasatti, S. J. Electroanel. Chem. 1992, 329, 237-246. Wandlowski. T.; de Levie, R. J. Elechoanal. Chem. 1993, 352, 279294. Schrettenbrunner, M.; Chaiyasith, P.; Baumg&el, H. Ber. Bunsenges. Phys. Chem. 1993, 97, 843-847, 847-459. Nikitas, P. J. Electroanel. Chem. 1993, 348, 59-80. Kurtyka, 8.; Kalsheva, M.;de Levie, R. J. Electroanal. Chem. 1992,347, 343-35 1. De Levle, R.; Vogt, A. J. Electroanel. Chem. 1992, 347, 353-360. Nikltas, P. J. Electroanal. Chem. 1991, 376,23-35. Nikitas, P.; Anastopoulos, A.; Papanastasiou, G. J. Electroanal. Chem. 1991, 377, 43-76. Nlkitas, P. Electrochlm. Acta 1993, 38, 1441-1451. Nikitas, P. Electrochlm. Acta 1992, 37, 81-90. Nikitas. P. Langmulr 1993, 9, 2737-2747. Nikitas. P. Electrochlm. Acta 1992, 37, 1919-1925. Matsul,T.; Jorwnsen, W.L. J.Am. Chem. Soc. 1992, 774,3220-3226. Marshall, S. L.; Conway, B. E. J. Electroanel. Chem. 1992, 337, 19-43, 45-66. Tilak. B. V.;Chen, C.-P.; Rangarajan, S. K. J. Electroanel. Chem. 1992, 324. 405-414. Diard, J.-P.; Le Gorrec, B.; Montella, C.; Montero-Ocampo, C. J. Ebctroanal. Chem. 1993, 352, 1-15. Harrington, D. A. J. Electroanel. Chem. 1993, 355, 21-35. Scott, K. J. Electroanel. Chem. 1992, 325, 1-22. Tilak, B. V.; Conway. B. E. Electrochim. Acta 1992, 37,51-61. Mlshra, A. K.; Bhattacharjee,6.;Rangarajan, S. K. J. Elecbpanal. Chem. 1992, 337,801-813. Rouquette, S.; Picard, 0. Electrochlm. Acta 1993, 38. 487-493. O'Dea, J. J.; Osteryoung, J. 0. Anal. Chem. 1993, 65, 3090-3097. O'Dea. J. J.; Ribes, A.; Osteryoung, J. G. J. Elechoanal. Chem. 1993. 345, 287-301. Reeves, J. H.; Song, S.;Bowden, E. F. Anal. Chem. 1993.65,683-688. Lovric, M.; Komorsky-Lovric, S.; Bond, A. M. J. Electroanal. Chem. 1991, 379, 1-18. Jaworskl, A.; Stojek, 2.; Scholz, F. J. Electroanal. Chem. 1993, 354, 1-9.
Analytical Chemistry, Vol. 66, No. 12, June 15, 1994
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Lovric, M.; Pizeta, I.; Komorsky-Lovric, S. Electroanalysis 1992, 4, 327-337. Freund, M. S.;BraJter-Toth, A. J. Phys. Chem. 1992, 96, 9400-9406. Dana. S. M.: Jablonski. M. E.: Anderson, M. R. Anal. Chem. 1993, 65, 1120-1122. Kano, K.; Uno, B. Anal. Chem. 1993, 65, 1088-1093. Schulz, C.; Spelser, B. J. Electroanal. Chem. 1993, 354, 255-271. Leverenz, A.; Speiser, B. J. Electroanal. Chem. 1991, 378, 69-89. Song, S.;Jln, W.; Wang, S.;He, P. J. Electroanal. Chem. 1992, 338, 61-72. Jin, W.; Song, S.;Wang, S.;He, P. J. Electroanal. Chem. 1992, 338, 73-84. Jin. W.; Cui, H.; Wang, S.Anal. Chim. Acta 1992, 268, 301-306. Engelman, E. E.; Evans, D. H. J. Elechoanal. Cbem. 1992, 337,739749. Molina, A.; Lopez-Tenes. M.; Serna, C.; Albaladejo, J. Bull. SOC.Chim. Belg. 1991, 700,703-716. Rouquette-Sanchez, S.; Picard, G. Electrochim. Acta 1993, 38, 487493. Verbrugge, M. W.; Baker, D. R.; Newman, J. Elechochlm. Acta 1993, 38, 1649-1859. Leibig, M.; Halsey, T. C. J. Electroanal. Chem. 1993, 358, 77-109. Zalis, S.; Posplsil, L.; Fanelli, N. J. Electroanal. Chem. 1993, 349, 443452. OCOn, P.; Herrasti, P.; Vazquez, L.; Salvarezza, R. C.; Vara. J. M.; ANia, A. J. J. Electroanal. Chem. 1991, 379, 101-110. Louch, D. S.;Pritzker, M. D. J. Electroanal. Chem. 1991, 379, 33-53. Gaunitz. U.; Lorenz, W. Z.Phys. Chem. 1992, 776, 121-126. Fawcett, W. R.; Filho, R. C. R. J. Chem. Soc., Faraday Trans. 1992, 88, 1143-1148. Schirmer, H.; Baumgartel, H. J. Electroanal. Chem. 1991, 376, 235253. Fontanesi, C. J. Chem. SOC.,Faraday Trans. 1992, 88, 3043-3046. Wandlowski, T.; de Levie, R. J. Electroanal. Cbem. 1993, 349, 15-30, Stenina, E. V.; Damaskin, B. B. J. Electroanal. Chem. 1993, 349, 3140. Hurwitz, H. D.; Jenard, A.; Bicamumpaka, 6.; Schmickler, W. J. flectroanal. Cbem. 1993, 349, 49-72. Thomas, F. G. J. Elechoanal. Chem. 1993, 349, 81-92. Zutlc, V.; Kovac, S.;Tomaic, J.; Svetlicic, V. J. Electroanal. Chem. 1993, 349, 173-186. Wandlowski. Th.; Chaiyasith, P.;Baumgartl, H. J. Electroanal. Chem. 1993, 346, 271-279. Buess-Herman, C.; Franck, C.; Gierst, L. J. Electroanal. Chem. 1992, 329,91-102. Wandlowski, T.; delevie, R. J. Electroanal. Chem. 1992,329, 103-127. Benedetti.L.; Gavioli, G. 6.; Fontanesi,C. J. Chem. Soc., Faraday Trans. 1992, 88, 843-847. Nikitas, P.; Pappa-Louisi, A. Electrochim. Acta 1993, 38, 1573-1584. Pama-Loulsi, A.: Nikitas. P.: Andonwlou, P. Electrochim. Acta 1993, 38: '1585-1590. Thomas, F. G.; Buess-Herman, C. J. Electroanal. Chem. 1991, 378, 399-405. Wandlowski, T.; Heyrovsky. M.; Novotny, L. Electrochim. Acta 1992, 37, 2663-2672. Jurkiewicz-Herbich, M. J. Electroanal. Chem. 1992, 332, 265-278. Werner, L.; Marlow, F.: Hill, W.; Retter, U. Chem. Phys. Lett. 1992, 794, 39-44. Demoz, A.; Harrison, D. J. Langmuir 1993, 9, 1046-1050. Parsons, R.; Payme, R. J. Electroanal. Chem. 1993, 357, 327-338. Parsons, R.; Peat, R. J. Chem. Soc.. Faraday Trans. 1993, 89, 181186. Ribes, A. J.; Osteryoung, J. J. Electroanal. Chem. 1991, 779,311-330. Garrido, J. A.; Robriguez, R. M.; Bastida, R. M.; Brlllas, E. J. Electroanal. Chem. 1992, 324, 19-32. Wandlowski, T.; de Levie, R. J. Elechoanal. Chem. 1993, 345, 413432. Wandlowski, Th. J. Electroanal. Chem. 1992, 333, 77-91. Wandlowski. T.: de Levie. R. Collect. Czech. Chem. Commun. 1993, 58, 29-40. PaDadODOUl OS, N.; Sotiropoulos, S.;Niktas, P. J. Elecfroanal. Chem. Papadopoulos, 1992, 324, 375-385. 1902, Tomaic, J.; Legovic, T.; Zutic, V. J. Electroanal. Chem. 1992, 322, 79-92. 79-92 . Baiazs, G. 6.; Anson, F. C. J. Electroanal. Chem. 1992, 335, 75-82. Balazs, G. B.; Anson, F. C. J. Electroanal. Chem. 1992, 322,325-345. Jaworski, J. S.; Kebede, 2.; Malik, M. J. Elechoanal. Chem. 1992, 333, 371-378. Pizeta, I.; Lovric. M.: Zelic, M.: Branica, M. J. Electroanal. Cbem. 1991, 378, 25-38. Anastopoulos, A.; Kaisheva, M. J. Electroanal. Chem. 1991,377, 279284. Philipp, R.; Retter. U. Thin Sol@Films 1992, 207, 42-50. Mattsson, G.; Nyholm, L.; Peter, L. M. J. Electroanal. Chem. 1993, 347, 303-326. Kikuchi, K.; Murayama, T. Bull. Chem. SOC.Jpn. 1993, 66, 437-443. Kruiit. W. S.:Sluvters-Rehbach. M.: Sluvters. J. H. J. flectroanal. Chem. 1993, 357, 115-135. Kneten, K. R.; McCreery, R. L. Anal. Chem. 1992, 64, 2518-2524. McDermott, M. T.; Kneten, K.:McCreery, R. L. J. Phys. Chem. 1992, 96. 3124-3130. Alsmeyer, D. C.; McCreery, R. L. Anal. Chem. 1992, 64, 1528-1533. McDermott, C. A.; Kneten, K. R.: McCreew, R. L. J. Electrochem. SOC. 1993, 740, 2593-2599. Alsmeyer. Y. W.; McCreery, R. L. Langmuir 1991, 7, 2370-2375. Sagara, T.; Niki, K. Langmuir 1993, 9, 831-838.
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Analytical Chemistry, Vol. 66, No. 12, June 15, 1994
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Goss, C. A.; Brumfield, J. C.; Irene, E. A,; Murray, R. W. Anal. Chem. 1993, 65, 1378-1389. Hendrlcks. S . A.: Kim. Y.-T.: Bard, A. J. J. Electrochem. SOC. 1992, 739, 2818-2824. McCarley, R. L.; Hendricks, S.A.; Bard, A. J. J. Phys. Chem. 1992, 96, 10089-10092 .- - - . .- - - . Zubimendl, J. L.; Vazquez, L.; Ocon, P.; Vara, J. M.; Triaca, W. E.; Salvarezza, R. C.; A ~ i a A. , J. J. Phys. Chem. 1993, 97, 5095-5102. Srlnivasan, R.; Gopalan, P. J. Phys. Chem. 1993, 97, 8770-8775. Keita, B.; Nadjo, L. J. Electroanal. Chem. 1993, 354, 295-296. Pocard, N. L.; Alsmeyer, D. C.; McCreecy, R. L.; Neeman, T. X.; Callstrom, M. R. J. Mater. Chem. 1992, 2, 771-784. Pontlkos. N. M.; McCreery, R. L. J. Electroanal. Chem. 1992, 324, 229-242. McDermott, M. T.; McDermott, C. A,; McCreery, R. L. Anal. Chem. 1993, 65, 937-944. Jaworski, R. K.; McCreery, R. L. J. Electrochem. SOC.1993, 140, 13601365. Zhang, H.; Coury, L. A., Jr. Anal. Chem. 1993, 65, 1552-1558. Firouzi, A.; Atanasoski, R . T.; Smyrl, W. H. J. Electroanal. Chem. 1992, 330, 369-380. Barbero, C.; Kotz, R. J. Electrochem. SOC. 1993, 140, 1-6. Marsh, J. H.; Orchard, S. W. Carbon 1992, 30, 895-901. Pocard, N. L.; Alsmeyer, D. C.; McCreery, R. L.; Neenan, T. X.; Callstrom, M. R. J. Am. Chem. Soc. 1992, 114, 769-771. Hutton, H. D.; Huang, W.; Alsmeyer, D. C.; Kometanl, J.; McCreery, R. L.: Neenan. T. X.: Calistrom. M.R. Chem. Mater. 1993. 5. 1110-1117. Tateishi, N:: Nishimura, K.; Yahikozawa, K.; Nakagawa,'M.; Yamada, M.; Takasu, Y. J. Electroanal. Chem. 1993, 352, 343-352. Ragoisha, G. A.; Jovanovic, V. M.; Aramov-Ivic, M. A.; Atanasoskl, R. T.; Smyrl, W. H. J. Electroanal. Chem. 1991, 379, 373-379. Casella, I.G.; Cataldi, T. R. I.; Saki, A. M.; Desimoni, E. Anal. Chem. 1993, 65, 3145-3150. Kulesza, P. J.; Lu, W.; Faulkner, L. R. J. Electroanal. Chem. 1992, 336, 35-44. Grinberg, V. A.: Kanevskii, L. S.;Cheblakova, E. G.; Mazln, V. M.; Dribinskii, A. V.; Cherstov, V.; Sterlln, S.R.; Vassll'ev, Yu. B. ElektYokhim 1992, 28, 864-869. Dribinskii, A. V.; Grinberg, V. A.; Kanevskii, L. S.;Avdalyan, M. 6.; Yakushev, V. V. Elektrokhimlya 1992, 28, 1718-1722. Kaplan, G. I.; Potapova, G. F.; Smlrnov, V. A. Elektrokhmlya 1993,29, 276-278. Chandrasekaran, M.; Noel, M.; Krishnan, V. Collect. Czech. Chem. Commun. 1991, 56, 2055-2066. Chandrasekaran, M.; Noel, M.; Krlshnan,V. J. Appl. Electrochem. 1992, 22, 1072-1076. Delamar. M.; Hitmi, R.; Pinson, J.; Saveant, J.-M. J. Am. Chem. SOC. 1992, 7 74, 5883-5884. Bourdillon, C.; Delamar, M.; Demallle, C.; Hitmi, R.; Molroux, J.; Pinson, J. J. Electroanal. Chem. 1992, 336, 113-123. Pantano, P.; Kuhr, W. G. Anal. Chem. 1993, 65, 2452-2458. Kawagoe, K. T.; Garris, P. A.; Wightman. R. M. J. Electroanal. Chem. 1993, 359, 193-207. Self, T. J.; Cresplt, F. J. Mater. Sci.: Mater. Med. 1992, 3, 418-425. Chun, B. W.; Davls, R . C.; He, Q.; Gustafson, R. R. Carbon 1992, 30, 177-178. Swain, G. M.; Kuwana, T. Anal. Chem. 1992, 64, 565-568. Thecdoridou, E.;Jannakoudakis, A. D.; Jannakoudakis, P. D.; Antoniadou, S. Can. J. Chem. 1992, 69, 1881-1885. Antonladou, S.; Jannakoudakis,A. D.; Jannakoudakis, P. D.; Theodoridou, E. J. Appl. Electrochem. 1992, 22, 1060-1064. Potje-Kamloth, K.; Josowicz, M. Ber. Bunsenges. Phys. Chem. 1992, 96, 1004-1017. Nakahara. M.; Shlmizu, K. J. Mater. Sci. 1992, 27, 1207-1211. Milhn, K. M.; Mikkelsen, S. R. Anal. Chem. 1993, 65, 2317-2323. McFadden, C. F.; Russell, L. L.; Melaragno, P. R.; David, J. A. Anal. Chem. 1992, 64, 1521-1527. Seeliger, W.; Hamnett, A. Ekctrochim. Acta 1992, 37, 763-765. Kashiwagi, Y.; Ono, H.; Osa, T. Chem. Lett. 1993, 257-260. Wang, J.: Angnes, L.; Tobias, H.; Roesner, R. A.; Hong, K. C.; Glass, R. S.;Kong, F. M.; Pekala, R. W. Anal. Chem. 1993, 65, 2300-2303. Swain, G. M.; Ramesham, R. Anal. Chem. 1993, 65, 345-351. Tenne, R.; Patel, K.; Hashlmoto, K.; Fujishima, A. J. Electroanal. Chem. 1993, 347, 409-415. Wring, S. A.; Hart, J. P. Analyst 1992, 1281-1286. Gilmartin, M. A. T.; Hart, J. P.; Birch, 8. Analyst 1992, 1299-1303. Zhao, S.; Korell, U.; Cuccia, L.; Lennox, R. B. J. Phys. Chem. 1992, 96, 5641-5652. Wang. J.; Naser, N.: Angnes, L.; Wu, H.; Chen, L. Anal. Chem. 1992, 64, 1285-1288. Kulesza, P. J.; Bandoch, M. J. Elecfroanal. Chem. 1992,323,131-147. Wdelov. A.: Larsson, R. Electrochlm. Acta 1992, 37, 187-197. Kobayaski, N.; Janda, P.; Lever, A. B. P. Inorg. Chem. 1992,37,51725177
(E138) Atoguchi, T.; Aramata, A.; Kazusaka, A,; Enyo, M. J. Electroanal. Chem. 1991. 378. 309-320. (E139) Zhang, J.; 'Anson, F. C. flectrochim. Acta 1993, 38, 2423-2429. (E140) Zhang. J.; Anson, F. C. J. Elecfmanal. Chem. 1992, 347, 323-341. (E141) Zhang, J.; Anson, F. C. J. ElectroaMl. Chem. 1993, 348, 81-97. (E142) Zhang, J.: Anson, F. C. J. Electroanal. Chem. 1993, 353, 265-280. (E143) Tse, Y.-H.; Seymour, P.; Kobayashi, N.; Lam, H.; Leznoff, C. C.; Lever, A. B. P. Inorg. Chem. 1991, 30, 4453-4459. (E144) Bond, A. M.; Scholz, F. Langmuir 1991, 7, 3197-3204. (E 145) Bond, A. M.;Colton, R.; Danlels, F.; Fernando,D. R.; Marken, F.; Nagaosa, Y.; Van Steveninck, R. F. M.; Walter, J. N. J. Am. Chem. SOC.1993, 7 75, 9556-9562.
(E146) Llorca, M. J.; Feliu, J. M.; Aklaz, A.;Claviller, J.; Rodes, A. J. Elechoanal. Chem. 1001, 376, 175-197. (E1471 Albalat, R.; Claret, J.; Orts, J. M.; Fellu, J. M. J. Elechoanal. Chem. 1002, 334, 291-307. (E1481 Sun, S.4.; Chen, A.C.; Huang, T.S.; Lln, J A . ; Tlan, 2. W. J. Electroanal. Chem. 1902, 340, 213-226. (E149) Avramoc-Ivlc, M.; Leger, J.-M.; Beden, 6.; Hahn, F.; Lamy, C. J. Elechoanal. Chem. 1003, 357, 285-297. (E150) Popovlc, K. 0.; Tripkovic, A. V.; Adzic, R. R. J. Elechoanal. Chem. 1002, 339. 227-245. (E151) Orts, J. M.; Fellu, J. M.; Aldaz, A. J. Elecfroanal. Chem. 1003, 347, 355-370. (E152) Baltruschat, H.; Schmiemann, U. Ber. Bunsenges. Phys. Chem. 1003, 97, 452-460. (E153) Schmiemann, U.; Baltruschat, H. J. Elechoanal. Chem. 1902, 340, 357-363. (E154) Markovic, N.; Ross, P. N., Jr. J. Phys. Chem. 1003, 97, 9771-9778. (E155) Elswlrth, M.; Lubke, M.; Krlscher, K.; Wolf. W.; Hudson, J. L.; Ertl, G. Chem. Phys. Lett. 1992, 792, 254-258. (E156) Ye, S.; Klta, H. J. Elechoanal. Chem. 1003, 346, 489-495. (E157) Rodes. A.; Gomez, R.; Orts, J. M.; Feliu, J. M.; AMaz, A. J. Electroanel. Chem. 1003, 359, 315-323. (E158) Ye, S.; Hattori, H.; Klta, H. Ber. Bunsenges. Phys. Chem. 1002, 96, 1884- 1885. (E159) Gomez, R.; Orts, J. M.; Rodes, A.; Feliu, J. M.; Aldaz, A. J. Electroanal. Chem. 1903, 358, 267-305. (E160) Nlshlhara, C.; Rasplni, I. A.; Kondoh, H.; Shlndo, H.; Kalse, M.; Nozoye, H. J. Electroanel. Chem. 1002, 338, 299-316. (E161) Gamboa-Akleco, M. E.; Herrero, E.; Zelenay, P. S.; Wieckowskl, A. J. Elechoanal. Chem. 1093, 348. 451-457. (E162) Faguy, P. W.; Markovlc, N.; Ross, P. N., Jr. J. Electrochem. Soc. 1003, 740, 1638- 1641. (E163) Nart, F. C.; Iwaslta, T.; Weber, M. Ber. Bunsenges. Phys. Chem. 1003, 97, 737-738. (E164) Marinkovlc, N. S.;Markovic, N. M.; Adzlc, R. R. J. Elechoanal. Chem. 1002, 330, 433-452. fE165) Llorca. M. J.: Feliu. J. M.: Aldaz. A,: Clavilier, J. J. Electroanal. Chem. 1003, '357, 299-319. (E166) . . Conwav, B. E.; Jerklewicz, G. J. Elechoanal. Chem. 1002, 339, 123146. (E167) Lang, P.; Claviller, J. Synth. Met. 1001, 45, 297-308. (E168) Upadhyay, D. N.; Kolb, D. M. J. Elechoanal. Chem. 1003, 358, 317325. (E169) Rodes, A.; Claviller, J. J. Electroanal. Chem. 1003, 344, 269-288. (E170) Morallon, E.; Vazquez, J. L.; AMaz, A.; Clavilier, J. J. Elechoanal. Chem. 1001, 376, 263-274. (E171) Cllment. M. A.: VaHs. M. J.: Feliu, J. M.: Alder, A.;ClavllIer, J. J.Ekfroana/. Chem. 1002, 326, 113-127. (E 172) Rodes, A.; Clavllier, J.; Orts, J. M.; Feliu, J. M.; Aldaz, A. J. Electroanal. Chem. 1002, 338, 317-338. (E173) Sumlno, M. P.; Shibata, S. J. Elechoanal. Chem. 1002,322,391-397. (E174) Sumino, M. P.; Shlbata, S. J. Elechoanal. Chem. 1002,336,329-348. (E175) Clavilier, J.; Rodes, A. J. Electroanel. Chem. 1003, 348, 247-264. (E176) Weaver, M. J.; Chang, S.-C.; Leung, L.-W. H.; Jiang, X.; Rubel, M.; Szklarczvk. M.: Zurawskl. D.: Wlechowski. A. J. E/echoana/.Chem. 1002, 327,' 247-260. (E177) Orts, J. M.; Fernandez-Vega, A,; Feilu, J. M.; Aldaz, A.; Clavilier, J. J. Electroanel. Chem. 1002, 327, 261-278. (E178) Hamelin, A. J. Elechoanal. Chem. 1002. 329, 247-258. (E179) Clavlller, J.; Albaiat, R.; Gomez, R.; Orts,J. M.; Feliu, J. M. J. Electroanal. Chem. 1003, 360, 325-335. (E180) Klta, H.; Naruml, H.; Ye, H.; Naohara, H. J. Appl. Electrochem. 1003, 23, 589-596. (E181) Clavlller, J.; Albaiat, R.; Gomez, R.; Orts,J. M.; Fellu, J. M.; Aldaz, A. J. Elechoanal. Chem. 1002, 330, 489-497. (E182) Morallon, E.; Vazquez, J. L.; Perez, J. M.; Beden, 6.; Hahn, F.; Leger, J. M.; Lamy, C. J. Elecfroanal. Chem. 1003, 344, 289-302. (E183) Orts. J. M.; Fellu, J. M.; AMaz, A. J. Electroanal. Chem. 1002, 323, 303-3 18. (E184) Franaszczuk, K.; Herrero, E.; Zelenay, P.; Wleckowski, A.; Wang, J.; Masel, R. I.J. Phys. Chem. 1002, 96. 8509-8516. (E185) Malta, G. N.; Hubbard, A. T. Cafal. Today 1002, 72, 465-479. (E 186) Gul, J. Y.; Stern, D. A.; Lln, C. H.; Gao, P.; Hubbard, A. T. Langmuir 1001, 7, 3183-3189. (E187) Gomez, R.; Clavllier, J. J. Elechoanal. Chem. 1993, 354, 189-208. (E188) Zurawski, D.; Wleckowski, A. Langmuir 1092, 8, 2317-2323. (E189) Lynch, M. L.; Corn, R. M. J. Elechoanal. Chem. 1001, 378, 379-386. (E190) Chang, S. C.; Ho, Y.; Weaver, M. J. Surf. Scl. 1002, 265, 81-94. (E191) Campbell, S. A.; Parsons, R. J. Chem. Soc., Faraday Trans. 1002, 88, a33-a41 - - - - . .. (E192) Jlang, X.; Chang, S.-C.; Weaver, M. J. J. Chem. Soc., Faraday Trans. 1993. ..., 89. ~.223-228. (E193) Evans, R. W.; Attard, G. A. J. Electroanal. Chem. 1093, 345,337-350. (E194) Markovic, N.; Ross, P. N. Langmuir 1003, 9, 580-590. (€195) Michaelis, R.; Zel. M. S.: Zhai, R. S.; Kolb, D. M. J. Elechoanal. Chem. 1002, 339. 299-310. (E 196) Dakkourl. A. S.;Batina, N.; Koib, D. M. Elecfrochlm. Acta 1003, 38, 2407-2472. (E197) shaft, D. P.; Twomey, T.; Plleth, W.; Schumacher, R.; Meyer, H. J. Elechoanal. Chem. 1002, 322, 279-268. (E198) Adzlc, R. R.; Feddrlx, F.; Nikolic, B. 2.;Yeager, E. J. Electroanal. Chem. 1002, 347, 287-306. (E199) Varga, K.; Zelenay, P.; Horlnyi, G.; Wieckowski, A. J. Elechoanal. Chem. 1002, 327, 291-306. (E200) Varga, K.; Zelenay, P.; Wieckowski, A. J. Elecfroanal. Chem. 1002, 330, 453-467. ,
I
.
~~~
~~~
(E201) Michaelis. R.; Kolb, D.M. J. Elechoanal. Chem. 1092, 329, 341-346. (E202) 361-368. Sashikata, K.; Furuya. N.; Itaya, K. J. Elechoanal. Chem. 1001, 376, (E203) Leung, L. W.; Gregg, T. W.; Goodman, D. W. Langmulr 1001, 7,32053210. (E2041 Leung, L. W.; Oregg, T. W.; Goodman. D. W. Chem. Phys. Lett. 1002, 188, 467-470. (E205) Gibson, N. C.; Savllle. P. M.; Harrlngton, D. A. J. Elechoanal. Chei. 1001. 378, 271-282. (E206) Zelenay, P.; Gamboa-Aldeco, M.; Horanyl, G.; Wieckowskl, A. J. Elechoanal. Chem. 1903, 357, 307-326. (E207) Rodrlquez, J. F.; Taylor, D. L.; Abruh, H. D. Elechochlm. Acta 1003, 38, 235-244. (E208) Inukal, J.; Ito, M. J. Elechoanal. Chem. 1003, 358, 307-315. (E209) Gomez, R.; Llorca. M. J.; Feliu, J. M.; Aldaz, A. J. Elechoanal. Chem. 1002, 340, 3490-355. (E210) Ross, P. N.; D'Agostlno, A. T. Ektrochlm. Acta 1002, 37, 615-623. (E211) Sholuda, P.; Kolb, D. M. Surf. Sci. 1002, 260, 229-234. (E212) Gao, X.; Weaver, M. J. J. Phys. Chem. 1003, 978685-8689. (E213) McCarley, R. L.; Bard, A. J. J. Phys. Chem. 1001, 95, 9618-9620. (E214) Tao, N. J.; Lindsay, S. M. J. Phys. Chem. 1092, 96, 5213-5217. (E215) Tao, N. J.; Lindsay, S. M. Surf. Scl. Lett. 1002, 274, L546-L553. (E216) Hamelin, A.; Gao, X.; Weaver, M. J. J. Elecfroanal. Chem. 1902, 323, 361-367. (E217) Gao, X.; Hamelin, A.; Weaver, M. J. Phys. Rev. B. 1002, 46, 7096. (E218) Skoluda, P.; Ha", U. W.; Kolb, D. M. J. Elechoanal.Chem. 1003,354, 289-294. (E219) Sun,S.G.;Yang,D.-F.;Wu,S.J.;Oclepa, J.;Lipkowski. J. J.E/ectroanel. Chem. 1003, 349, 211-222. (E220) Ha". U. W.; Kolb, D. M. J. Elechoanal. Chem. 1002, 332,339-347. (E221) Kim, Y.-T.; McCatley, R. L.; Bard, A. J. J. Phys. Chem. 1002, 96,74167421. (E222) Skoluda, P.; Holzle, M.; Llpkowskl, J.; Kolb, D. M. J. Elechoanal. Chem. 1003. 358, 343-349. (E223) McCarley, R. L.; Bard, A. J. J. Phys. Chem. 1002, 96, 7410-4716. (E224) McCartey. R. L.; Kim, Y.-T.; Bard, A. J. J. Phys. Chem. 1003, 97, 211215. (E225) Nichols, R. J.; Beckmann, W.; Meyer, H.; Batina, N.; Kolb, D. M. J. Elechoanal. Chem. 1002, 330, 381-394. (E226) Batina, N.; Kolb, D. M.; Nichols. R. J. Langmulr 1002, 8, 2572-2576. (E227) Gao, X.; Weaver, M. J. J. Am. Chem. SOC. 1002, 774, 9544-9551. (E228) Pettlnger, 8.; Lipkowskl, J.; Mirwald, S.; Friedrich, A. Surf. Scl. 1002, 269-270, 377-382. (E229) Pettlnger, 6.; Lipkowski, J.; Mirwald, S.; Friedrich, A. J. Elechoanal. Chem. 1002, 329, 289-31 1. (E230) Koas, D. A.; Richmond, G. L. J. Phys. Chem. 1092, 96, 3770-3775. (E231) Ullmann, R.; Will, T.; Kolb, D. M. Chem. Phys. Lett. 1993,209,238-242. DeRose, J. A.; Lindsay, S. M. (E2321 Tao, N. J.; Pan, J.; LI, Y.; Oden, P. I.; Surf. Sc;. Lett 1002, 277, L338-L344. (E233) Chen, C.; Gewlrth. A. A. Phys. Rev. Lett. 1002, 68, 1571. (E234) Samant, M. G.; Borges, 0.; Melroy, 0. R. J. Elechochem. Soc.1003, 740, 421-425. (E235) Suglta, S.; Abe. T.; Itaya. K. J. Phys. Chem. 1003, 97, 8780-8785. (E236) Chen, C.; Vesecky, S. M.; Gewlrth, A. A. J. Am. Chem. SOC.1002, 7 74, 451-458. (E237) Chen, C.; Washburn, N.; Gewlrth, A. A. J. Phys. Chem. 1003, 97.97549760. (E238) Chen, C.; Gewlrth. A. A. J. Am. Chem. Soc.1002, 774, 5439-5440. (E239) Chen, C.; Kepler, K. D.; Gewlrth, A. A.; Ocko, B. M.; Wang, J. J. Phys. Chem. 1003, 97, 7290-7294. (E240) Villegas, I.; Stlckney, J. L. J. Electrochem. SOC.1002. 739. 686-694. (E241) Vlliegas, I.; Stlckney, J. L. J. Vac. Sci. Techno/.,A 1002, 70, 30323038. nodes, 0. Langmulr 1002, 8, (E242) Golan, Y.; Margulls, L.; Rubenstein, I.; 749-752. (E243) Skoluda, P.; Dutkiewlcz, E. J. Electroanal. Chem. 1092,329, 279-287. (E244) Richer, J.; Iannelli, A.; Lipkowski, J. J. Electroanal. Chem. 1002, 324, 339-358. (E245) Stolberg, L.; Lipkowski, J.; Irish, D. E. J. Electroanal. Chem. 1002, 322, 357-372. (E2461 Yang, D. F.; Stolberg, L.; Lipkowskl, J.; Irish, D. E. J. Elechoanal. Chem. 1992, 329, 259-278. (E247) Tao, N. J.; DeRose, J. A.; Lindsay, S. M. J. Phys. Chem. 1903, 97.910. (E248) No& J. J.; Blzzotto, D.; Llpkowski, J. J. Elechoanal. Chem. 1003, 344, 343-354. (E249) Lecoeur, J.; Bellier, J. P.; Koehler. C. J. Elechoanal. Chem. 1092, 337, 197-216. (E250) Xing, X.; Shao, M.; Hslao, M. W.; Adzlc, R. R.; Llu, C . C . J. Elechoanal. Chem. 1002. 339, 211-225. (E251) Hamelln. A.; Forestl, M. L.; Guldelii, R. J. Elechoanal. Chem. 1003,346, 251-259. (E252) ForesB, M. L.; GuMelll,R.; Hamelln. A. J. Electroenal. Chem. 1003.346, 73-83. (E253) Jovic, V. D.; Parsons, R.; Jovic. B. M. J. Elechoanal. Chem. 1002, 339. 327-337. (E2541 Doubova. L. M.; Hamelln, A.; Stoicoviciu, L.; Trasatti, S. J. Elechoanal. Chem. 1002, 325, 197-205. (E2551 CaO, E. Y.; -0. P.; Gul, J. Y.; Lu, F.; Stern, D. A,; Hubbard, A. T. J. Elechoanal. Chem. 1002, 339, 31 1-325. (E256) Stalkov, G.; Budevski, E.; Obretenov, W.; Lorenz, W. J. J. Elechoanal. Chem. 1003, 349, 355-363. (E257) Mao, B. W.; Tian. 2. Q.; Fieischmann. M. Elechochlm. Acta 1002. 37, 1767-1770. (E258) Lorenz, W. J.; Gassa,L. M.; Schmldt, U.; Obretenov, W.; Staikov, 0.; Bostanov, V.; Budevski, E. Elechochlm. Acta 1002, 37, 2173-2178.
Analytical Chemistry, Vol. 86, No. 12, June 15, 1994
417R
(E259) McBride, J. R.; Schlmpf, J. A.; Soriaga, M. P. J. Am. Chem. SOC.1002, 774, 10950-10952. (E260) Berry, G. M.; McBride, J. R.; Schimpf, J. A,; Soriaga, M. P. J. Electroanal. Chem. 1003, 353, 281-287. (E261) . , McBride. J. R.: SChlmDf, J. A,; Soriaaa. M. P. J. Electroanal. Chem. 1003, 350, 317-320. ' (E262) Lenz, P.; Solomun, T. J. Electroanai. Chem. 1003, 353, 131-145. (E263) Baldauf, M.; Kolb, D. M. Electrochim. Acta 1003, 38, 2145-2153. (E264) Chang, S . 4 . ; Ho, Y.; Weaver, M. J. J. Electrochem. SOC.1002, 739, 147-152. (E265) Zelenay, P.; Wieckowski, A. J. Electrochem. SOC.1002, 739, 25522558. (E266) Ahmadi, A.; Evans, R. W.; Attard, G. J. Electroanal. Chem. 1093, 350, 279-295. (E267) Cao, E. Y.; Stern, D. A,; Gui, J. Y.; Hubbard, A. T. J. Electroanal. Chem. 1003, 354, 71-86. (E268) Wang, K.; Chottlner, G. S.; Scherson, D. A. J. Phys. Chem. 1003, 97, 10108-10111. . - . - - .- . . .. (E269) Borges, G. L.; Samant, M. G.; Ashley, K. J. Electrochem. SOC.1002, 739, 1585-1568. (E270) Cruickshank, B. J.; Sneddon, D. D.; Gewlrth, A. A. Surf. Sci. Lett. 1003, 28 7, L308-L314. (E271) . . Yau. S.-L.: Fan. F.-R. F.; Bard, A. J. J. Electrochem. SOC.1002, 739, 2825-2829. (E272) Vqel, R.; Kamphausen, I.; Baltruschat,H. Ber. Bunsenges.Phys. Chem. 1902, 96, 525-530. (E273) Gao, X.: Weaver, M. J. Ber. Bunsenges. Phys. Chem. 1003, 97,507516. (E274) Schmlckler, W.; WMrig, C. J. Electroanal. Chem. 1002, 336, 213-221. (E275) Henderson, D.; Chan, K.-Y. J. Electroanal. Chem. 1002,330,395-406. (E276) Fotino, M. Rev. Sci. Instrum. 1003, 64, 159-167. (E277) Hocket, L. A.; Creager, S. E. Rev. Scl. Instrum. 1003, 64, 263-264. (E278) Roblnson, R. S.; Wdrig, C. A. Langmulr 1002, 8, 2311-2316. (E279) Bach, C. E.; Nichols, R. J.; Bechmann, W.; Meyer, H.; Schulte, A,; Besenhard, J. 0.; Jannakoudakis, P. D. J. Electrochem. SOC. 1003, 740, 1281-1283. (E280) Brumfield, J. C.; Goss, C. A.: Irene, E. A.; Murray, R. W. LangmulrlOO2, 8. 2810-2817. ., -. . -. (E281) Yang, H.; Fan, F A . F.; Yau, S.-L.; Bard, A. J. J. Electrochem. SOC. 1002. 739. 2182-2185. (E282) G0ss;C. A:; Brumfield, J. C.; Irene, E. A,; Murray, R. W. LangmuirlOOP, 8, 1459-1463. (E283) Creager, S. E. J. Phys. Chem. 1002, 96, 2371-2375. (E284) Suglmoto, H.; Shimo, N.; Kltamura, N.; Masuhara, H.; Itaya, K. J. Electroanal. Chem. 1003, 346, 147-160. (€285) Engstrom, R. C.; Small, 6.; Kattan, L. Anal. Chem. 1002, 64, 241-244. (E266) Wlpf, D. 0.; Bard, A. J.; Tallman, D. E. Anal. Chem. 1003, 65, 13731377. (E287) Oppenheim, I.C.; Trevor, D. J.; Chdsey, C. E. D.; Trevor, P. L.; Sieradzki, K. Sclence 1001, 254, 687-689. (E268) Cruickshank, B. J.; Gewlrth, A. A,; Rynders, R. M.; Alkire, R. C. J. Eiectrochem. SOC.1002, 739, 2829-2832. (E289) Pontifex, G. H.; Zhang, P.; Wang, 2 . ; Haslett, T. L.; AIMawlawi, D.; Moskovlts, M. J. Phys. Chem. 1001, 95, 9989-9993. (E290) Li, S.; White, H. S.; Ward, M. D. Chem. Mater. 1002, 4, 1082-1091. (E291) Chen, J.-S.; Devlne, T. M.: Ogletree, D. F.; Salmeron, M. Surf. S d 1001, 258, 346-356. (E292) Gomez-Rodrlquez, J. M.; Baro, A. M.; Vazquez, L.; Salvarezza. R. C.; Vara, J. M.; A ~ l a A. , J. J. Phys. Chem. 1002, 96, 347-350. Lyubchenko, Y. (E293) Lindsay, S. M.; Tao, N. J.; De Rose, J. A.; Oden, P. I.; L.; Harrington, R. E.; Shlyakhtenko, L. Biophys. J. 1002, 67, 15701584. (E294) Allison, D. P.; Bottomley, L. R.; Thundat, T.; Brown, G. M.; Woychik, R. P.; Schrlck, J. J.; Jacobson, K. 6.; Warmack, R. J. Proc. Natl. Acad. SCi. U.S.A. 1002, 89, 10129-10133. (E295) Engstrom, R. C.; Ghaffarl, S.; Qu, H. Anal. Chem. 1002, 64, 25252529. (E296) Miller, C. J.; McCord, P.; Bard, A. J. Langmuir 1001, 7, 2781-2787. (E297) Llllard, R. S.; Moran, P. J.; Isaacs, H. S. J. Electrochem. SOC. 1002, 739, 1007-1012. (E298) Llpkowski, J.; Stolberg, L.; Morin, S.; Irish, D. E.; Zelenay, P.; Gamboa, M.; Wieckowski, A. J. Eiectroanal. Chem. 1903, 355, 147-163. (E299) Bockrls, J. O'M.; Gamboa-Aldeco, M.; Szklarczyk, M. J. Electroanal. Chem. 1002, 339, 355-400. (E300) Bockrls, J. O M ; Jeng, K.T. J. Eiectroanai. Chem. 1002,330,541-581. (E301) Dicklnson, K. M.: Hanson, K. E.; Fredlein, R. A. Electrochim. Acta 1002, 37, 139-141. (E302) Borkowska, 2 . ; Jarzabek, G. J. Elechoanal. Chem. 1003, 353, 1-17 (E303) Aramata, A.: Toyoshima, I.; Enyo, M. Electrochim. Acta l W 2 . 37, 13 17-1320. (E304) Franaszczuk, K.; Sobkowski, J. J. Electroanai. Chem. 1002, 327, 235245. (E305) Wang, S.-R.; Fedkiw, P. S . J. Electrochem. SOC.1002, 739, 25192525. (E306) Gasteiger, H. A.; Markovlc, N.; Ross, P. N., Jr.; Cairns, E. J. J. Phys. Chem. 1003, 97, 12020-12029. (E307) Kunugl, Y.; Nanaku, T.; Chong, Y.-6.; Watanabe, N. J. Electroanai. Chem. 1003, 353, 209-215. (E308) Iwasita, T.; Nart, F. C. J. Eiectroanal. Chem. 1001, 377, 291-298. (E309) Zhang, Y.; Weaver, M. J. Langmuir 1W3, 9, 1397-1403. (E310) Zapien, D. C.; Gul, J. Y.; Stern, D. A.; Hubbard, A. T. J. Eiectroanal. Chem. 1002, 330, 469-467. (E311) Chang, S . 4 . ; Ho, Y.; Weaver, M. J. J. Am. Chem. SOC. 1001, 773, 9506-95 13. (E312) Hlavaty. J.; Volke, J. Collect. Czech. Chem. Common. 1002, 57, 429438.
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Analytical Chemistty, Vol, 66,No. 12, June 15, 1994
(E313) Gattrell, M.; Kirk, D. W. J. Electrochem. SOC.1003. 740, 1534-1540. (E314) Rhodes, A.; Perez, J. M.:Orts, J. M.; Fellu, J. M.; Aldaz, A. J. Electroanal. Chem. 1003, 352, 345-352. (E315) Weisshaar, D. E.; Walczak, M. M.; Porter, M. D. Langmulr 1003, 9. 323-329. (E316) Claviller, J.; Svetllcic, V. J. Electroanal. Chem. 1002, 322, 405-409. (E317) Svetlicic, V.; Clavllier, J.; Zutlc, V.; Chevalet, J.; Elachi, K. J. Electroanel. Chem. 1093, 344, 145-160. (€318) Shu, 2 . X.; Bruckenstein, S.J. Electroanai. Chem. 1001,3 77,263-277. (E319) Michelhaugh, S.L.: Carrasquillo, A,, Jr.; Sorlaga, M. P. J. Electroanal. Chem. 1001, 7 79, 387-394. (E320) Hsiao, Y.-L.; V i , J. E.; Johnson, D. C. J. Electrochem. SOC.1002, 739, 377-380. (E321) Brevett, C. A. S.;Johnson, D. C. J. Electrochem. SOC. 1002, 739, 1314- 13 19. (E322) Wllllams, D. G.; Johnson, D. C. Anal. Chem. 1002, 64, 1785-1789. (E323) Conway, B. E.; Gu, P. J. Electroanel. Chem. 1003, 349, 233-254. (E324) Nakabayashi, S.; Klra, A. J. Phys. Chem. 1002, 96, 1021. (E325) Okamoto, H.; Tanaka, N. Electrochim. Acta 1003, 38, 503-509. (E326) Okamoto, H.; Tanaka, N. Electrochim. Acta 1003, 38, 503-509. (E327) Okamoto, H. Electrochim. Acta 1002, 37, 37-42. (E328) Wolf, W.; Ye, J.; Purgand, M.; EiswCth, M.; Doblhofer, K. Ber. Bunsenges. Phys. Chem. 1002, 96, 1797-1804. (E329) InzeR, G.; Kertesz, V. Electrochim. Acta 1003, 38, 2385-2386. (E330) Schneider, F. W.; Hauser, M. J. B.; Reislng, J. Ber. Bunsenges. Phys. Chem. 1003, 97, 55-58. (E331) Birss, V. I.; Chang, M.; Segal. J. J. Electroanel. Chem. 1003, 355, 181-191. Goledzlnowski, M. J. Electroanel. Chem. 1003, 357, 227(E332) Birss, V. I.; 243. (E333) Burke, L. D.; Casey, J. K. Electrochim. Acte 1002, 37, 1617-1829. (E334) Burke, L. D.; O'Dwyer, K. J. Electrochim. Acta 1002, 37, 43-50. (E335) Heyd, D. V.: Harrington, D. A. J. Electroanel. Chem. 1002,335, 19-31. (E336) Schumacher, R.; Helblg, W.; Hass, I.; Wunsche, M.; Meyer, H. J. Electroanai. Chem. 1003, 354. 59-70. (E337) Bourkane, S.; Gabrlelli, C.; Keddam, M. Electrochim. Acta 1903, 38, 1827-1835. (E338) Burke, L. D.; O'Sullivan, J. F. Electrochim. Acta 1002, 37, 585-594. (E339) Burke, L. D.; Cunnane, V. J.; Lee, B. H. J. Electrochem.SOC.1002, 739, 399-406. (E340) Roberts, R.; Johnson, D. C. Electroanalysis (N.Y.) 1092, 4, 741-749. (E341) Bolzan, A. E.; AN^, A. J. J. Electroanal. Chem. 1003, 354, 243-253. (E342) Creus. A. H.; Carro, P.; Gonzalez, S.; Salvarezza, R. C.; ANia, A. J. J. Electrochem. SOC. 1002, 739, 1064-1070. (E343) Burstein, G. T.; Clnderey, R. J. Corros. Scl. 1901, 32, 1195-121 1. (E344) Peck, S. R.; Curtin, L. S.; McDevitt, J. T.; Murray, R. W.; Collman, J. P.; Little, W. A.; Zetterer, T.; Duan, H. M.; Dong, C.; Hermann, A. M. J. Am. Chem. SOC.1002, 774, 6771-6775. (E345) Engelhardt, 1.; Speck, R.; Inche, J.; Khalil, H. S.; Ebert, M.; Lorenz, W. J.; Saemann-Ischenko, G.; Breiter, M. W. Electrochim. Acta 1002, 37, 2129-2136. (E346) (;reen, S. J.; Rosselnsky, D. R.; Toohey, M. J. J. Am. Chem. SOC.1002, 114 . . , 9702-9704 - . - - - . - .. (€347) Kuznetsov, A. M. Electrochim. Acta 1002, 37, 2123-2128. (E346) Rosamilia, J. M.; Glarum, S. H.; Cava, R. J.; Batlogg, B.; Miller, B. Physica C 1901, 182, 285-290. (E349) Bhattacharya, R. N.; Parilla, P. A.; Noufi, R.; Arendt, P.; Elllott, N. J. Electrochem. Soc. 1002, 739, 67-69. (E350) Morikawa, Y.; Satoh, K.; Ozawa, S.;Nakamura, K.; Yamamoto, H.; Tanaka, M. Physics C (Amsterdam)1001, 785- 789, 431-432. (E35 1) Izakovlch, E. N.; Geskin, V. M.: Stepanov, S. V. Synth. Met. 1002, 46, 71-77. (E352) Haupt, S. G.; Riley, D. R.; Jones, C. T.; Zhao, J.; McDevitt, J. T. J. Am. Chem. Soc. 1003, 715, 1196-1196. (E353) Scheurell, S.: Scholz, F.; Olesch, T.; Kemink, E. S m c o n d . Sd.Techno/. 1002, 5,303-305. (E354) Ma, S. M.; Chang, Y. S.;Yang, F. L.; Li, C. S.; Huang, Y. T.; Lee, W. H. J. Electrochem. SOC.1002, 139, 1951-1955. (E355) Nakabayashi, S.; Klra, A. J. Electroanel. Chem. 1001, 779, 381-385. (E356) Graves, J. E.: Pletchec, D.; Clarke, R. L.; Walsh, F. C. J. Appl. Electrochem. lQ92. 200-203. ... 22. -. . -. . . (E357) Graves, J. E.; Pletcher, D.;Clarke,R. L.; Walsh, F.C. J. Appl. Ektrochem. 1001. 27. 848-857. (E358) B a c i , R:; Ravindranathan, P.: Dougherty, J. P. J. Mater. Res. 1002, 7, 423-428.
-. --.
F. MODIFIED ELECTRODES
Frksch-Faules, I.; Faulkner, L. R. J. Electroanai. Chem. 1002, 331, 997-1014. FrRsch-Faules, 1.; Faulkner, L. R. Anal. Chem. 1002, 64, 1118-1 127. Fritsch-Faules, I.; Faulkner, L. R. Anal. Chem. 1002. 64, 1127-1131. Larsson, H.; Lindholm, B.; Sharp, M. J. Electroanai. Chem. 1002, 336, 263-279. Blauch, E. N.; Saveant, J . 4 . J. Am. Chem. Soc. 1002, 774, 33233332. Blauch, D. N.; Saveant, J . 4 . J. Phys. Chem. 1003, 97, 6444-6448. Mohan, L. S.; Sangaranarayanan, M. V. J. Electroanal. Chem. 1002, 323, 375-379. Delss, E.; Haas, 0.:Daul, C. J. Electroanai. Chem. 1002,337,299-324. Ren. X.: Pickup. P. G. J. Electrochem. Soc. 1002, 739, 2097-2105. Ren, X.; Pickup, P. G. J. Phys. Chem. 1003, 97, 5356-5362. Ren, X.; Pickup, P. G. J. Chem. SOC.,Faraday Trans. 1003, 89, 321326. Fletcher, S.J. Chem. Soc., Faraday Trans. 1003, 89, 311-320. Fletcher, S . J. Electroanal. Chem. 1002, 337, 127-145.
Albery, W. J.; Mount, A. R. J. Chem. SOC.,Faraday Trans. 1993, 89, 327-331. Albery, W. J.; Mount, A. R. J. Chem. Soc., Faraday Trans. 1993, 89, 2487-2497. Mathias, M. F.; Haas, 0. J. Phys. Chem. 1992, 96, 3174-3182. Mathias, M. F.; Haas, 0. J. Phys. Chem. 1993, 97, 9217-9225. Ren. X.; Pickup, P. G. J. Phys. Chem. 1983, 97, 3941-3943. Albery, W. J.; Elliott, C. M.; Mount, A. R. J. Electroanal. Chem. 1990, 288, 15-34. Cai, 2.; Marin, C. R. Synth. Met. 1992, 46, 165-179. Sharp, M.; Llndholm-Sethson,B.; Lind, E.-L. J. Electroanel. Chem. 1993, 345, 223-242. Forster, R. J.; Vos, J. G. Electrochim. Acta 1992, 37, 159-167. Forster, R. J.; Vos, J. G. J. Electrochem. SOC.1992, 739, 1503-1509. Lee, C.; Anson, F. C. Anal. Chem. 1992, 64, 528-533. Mao, H.; Pickup, P. 0. Chem. Meter. 1992. 4, 842-645. Aoki, A.; Helier, A. J. Phys. Chem. 1993, 97, 11014-11019. Kelly, A. J.; Oyama, N. J. Phys. Chem. 1991, 95, 9579-9584. Hillman, A. R.; Hughes, N. A.; Bruckenstein, S. J. Electrochem. SOC. 1992, 139, 74-77. Inzelt, G.; Bacskai, J. Electrochlm. Acta 1992, 37, 647-654. Hillman, A. R. J. Electroanal. Chem. 1993,356, Clarke, A. P.; Vos, J. 0.; 287-293. Miras,M:C.; Barbero, C.; K&, R.; Haas, 0.;Schmidt, V. M.J. fktroanal. Chem. 1992. 338. 279-297. Kulesza, P. J.; caius, Z.J. E/ectroana/. c b m . 1992, 323, 261-274. Lang, G.; Bacskal, J.; Inzelt, G. Electrochim. Acta 1993,38,773-760. Mlcka, K. flectrochim. Acta 1993, 38, 1433-1439. Amemiya, T.; Hashimoto, K.; Fujishima, A. J. Phys. Chem. 1993, 97, 4192-41 95. Amemiya, T.; Hashimoto, K.; Fujishima, A. J. Phys. Chem. 1993, 97, 9736-9740. Hillman, A. R.; Bruckenstein, S. J. Chem. Soc., Faraday Trans. 1993, 89, 339-348. Bruckenstein, S.; Wiide, C. P.; Hillman, A. R. J. Phys. Chem. 1993, 97, 6853-6858. Bruckenstein, S.; Hillman, A. R. J. Phys. Chem. 1991, 7997, 1074810752. Takehara, K.; Ide, Y. Bioelectrochem. Bloenerg. 1991, 26, 297-305. Wrighton, M. S. J. Phys. Chem. Tatistcheff, H. 6.; Frltsch-Fauies, I.; 1993, 97, 2732-2739. Lyons, M. E. G.; Bartiett, P. N. J. Electroanel. Chem. 1991, 316. 1-22. Lyons, M. E. G.; Lyons, C. H.; Mlchas, A.; Bartlett, P. N. Analyst 1992, 1271-1280. Xie, Y.; Anson, F. C. J. Electroanel. Chem. 1993, 344, 405-411. Xle, Y.; Anson, F. C. J. flectroanal. Chem. 1993, 349, 325-340. Sabatani, E.; Anson, F. C. J. Phys. Chem. 1993, 97, 10158-10165. Shi, C.; Anson, F. C. J. Am. Chem. SOC. 1991. 773, 9564-9570. Zeng, 2. Y.; Gupta, S. L.; Huang, H.; Yeager, E. B. J. Appl. flectrochem. 1991, 27, 973-981. Kawashima, M.; Sato, Y.; Niushima, K.; Sato, M.; Sakaguchi, M. J. Electroanal. Chem. 1991, 376,293-304. El Hourch, A.; Belcadi, S.; Moisy, P.; Crouigneau, P.; Leger, J.-M.; Lamy, C. J. Electroanal. Chem. 1992, 339, 1-12. Yoshida, T.; Iida, T.; Shirasagi, T.; Lin, R.J.; Kaneko, M. J. Electroanal. Chem. 1993, 344, 355-362. Ogura, K.; Mine, K.; Yano, J.; Suglhara, H. J. Chem. Soc., Chem. Commun. 1993, 20-2 1. Doherty, A. P.; Vos, J. G. J. Chem. Soc., Faraday Trans. 1992, 88. 2903-2907. Dohertv. A. P.; Forster, R. J.; Smyth, M. R.; Vos, J. G. Anal. Chlm. Acta 1991, 255, 45-52. Younathan, J. N.; Wood, K. S.; Meyer, T. J. Inorg. Chem. 1992, 37, 3280-3265. Wang, B.; Song, F.; Dong, S. J. €lec?roanal. Chem. 1993, 353,43-55. Dong, S.; Jin, W. J. Electroanel. Chem. 1993, 354, 87-97. Wei, C.; German, S.; Basak, S.; Rajeshwar. K. J. Electrochem. SOC. 1093. ...-, 140. . . ., L60-L62. -.. -. -. Arai, 0.; Sugaya, T.; Sakamoto, M.; Yasumori, I.Bull. Chem. SOC.Jpn. 1992. 65. 594-596. Furbee, J: W., Jr.; Thomas, C. R.; Kelly, R. S.; Malachowski, M. R. Anal. Chem. 1993, 65, 1654-1657. Deronzier, A.; Moutet, J.4.; Salnt-Aman, E. J. flectroanal.Chem. 1992, 327, 147-158. Chardon-Noblat, S.; Cosnler, S.; Deronzier, A,; Vlachopoulos, N. J. Electroanal. Chem. 1993, 352, 213-228. Miaw, C.-L.; Hu, N.; Bobbw, J. M.; Ma, 2.; Ahmadi, M. F.; Rushing, J. F. Langmuir 1993, 9, 315-322. Ohsaka, T.; Tanaka, K.; Tokuda, K. J. Chem. SOC.,Chem. Commun. 1993, 222-224. Kashiwagi, Y.; Osa, T. Chem. Le??.1993, 677-680. Hale, P. D.; Lee, H A . ; Okamoto, Y. Anal. Le??.1993, 26, 1073-1085. Cauquls, G.; Cosnier, S.; Deronzier, A.; Galland, 6.; Llmosln, D.; Moutet, J.C.; Bizot, J.; Deprez, D.; Pullcanl, J.-P. J. flectroanal. Chem. 1093, 352,181-195. Wong. K.-Y.; Yam, V. W.-W.; Lee, W. W.4. flectrochlm. Acta 1982, 37, 2645-2650. DeGiovani, W. F.; Deronzier,A. J. flectroanal. Chem. 1992,337,285298. Fish, J. R.; Kubaszewskl, E.; Peat, A.; Malinski, T.; Kaczor, J.; Kus, P.; Czuchajowski, L. Chem. Meter. 1992, 4, 795-803. Kubaszewskl, E.; Bennett, J.; Tomboulian, P.; Maiinski,T.; Czuchajowski, L.; Kiechle, F. Appl. Surt Scl. 1993, 65-66, 355-361. Hamnett, A.; Stevens, P. S.; Wingate, R. D. J. Appl. Electrochem. 1991, 27. 982-985.
(F73) (F74) (F75) (F76) (F77) (F78) (F79) (F60) (F81) (F82) (F83) (F84) (F85) (F86) (F87) (F88) (F89) (F90) (F91) (F92) (F93) (F94) (F95) (F96) (F97) (F98) (F99) (F100) (F101) (F102) (F103) (F104) (F105) (F 106) (F107) (F108) (F109) (F1IO) (F111)
( F I 12) (F113) (F114) (F115) (F116) (F117) (F118) (F119) (F120) (F121) (F122) (F123) (F124) (F125) (F126) (F127) (F128) (F129)
Ye, L.; Mmmerle, M.; Olsthoorn, A. J. J.; Schuhmann, W.; Schmidt, HA.; Duine, J. A.; Heller, A. Anal. Chem. 1993, 65, 238-241. Yon-Hin, B. F. Y.; Smoiander, M.; Crompton, T.; Lowe, C. R. Anal. Chem. 1993, 65. 2067-2071. Bartlett, P. N.; Birkin, P. R. Anal. Chem. 1993. 65, 1118-1119. Anzai. J.; Hoshi, T.; Osa, T. Chem. Le??.1993, 1231-1234. Arai, 0.; Hayashi, M.; Noma, T.; Yasumoti, I . Chem. Le??.1993, 10811064. Khan, 0. F.; Kobetake, E.; Ikarlyama, Y.; Aizawa, M. Anal. Chlm. Acta 1893, 287, 527-533. Wang, D. L.; Helkr, A. Anal. Chem. 1993, 65, 1069-1073. Vreeke, M.; Malden, R.; Helkr, A. Anal. Chem. 1992, 64.3084-3090. Tatsuma, T.; Gondalra, M.; Watanabe, T. Anal. Chem. 1922,64, 11831187. Shl, C.; Anson, F. C. Inorg. Chem. 1992, 37,5078-5083. Steiger, B.; Shi, C.; Anson, F. C. Znorg, Chem. 1993, 32, 2107-2113. Arifuku, F.; Mori, K.; Muratani, T.; Kurihara, H. Bull. Chem. Soc. Jpn. 1992, 65, 1491-1495. Nobayaski, N.; Janda, P.; Lever, A. B. P. Inorg. Chem. 1992,3 1,51725177. Aklba, U.; Nakamura, Y.; Suga, K.; Fujlhira, M. Thln SolMFilms 1992. 2 1012 7 1, 38 1-383. Roslonek, G.; Taraszewska, J. J. Electroanal. Chem. 1992, 325.285300. Chen, K.; Herr, 8. R.; Singewald, E. T.; Merkin, C. A. Langmuir 1992, 8, 2565-2587. Verbrugge, M. W.; SchneMer, E. W.; Coneli, R. S.; Hill, R. F. J. Electrochem. Soc. 1992. 739. 3421-3428. Zawodzinski, T. A., Jr.; Derouin, C.; Radzinski, S.; Sherman, R. J.; Smith, V. T.; Springer. T. E.; Gottesfeld, S. J. Electrochem. Soc. 1993, 740, 1041-1047. Porat, 2.; Rubinstein. I.; Zinger, B. J. Electrochem. Soc. 1993, 740, 2501-2507. Lin, R.J.; Onikubo, T.; Nagai, K.; Kaneko, M. J. Electroanel. Chem. 1993, 348, 189-199. Cha, C. S.; Chen, J.; Liu, P. F. J. flectroanal. Chem. 1993, 345, 463467. Parthasarathy, A.; Dave, 6.; Srlnivasan, S.; Appiey, A. J.; Martin, C. R. J. Electrochem. SOC. 1992, 139, 1834-1641. Parthasarathy, A.; Srinivasan, S.; Appleby, A. J.; Martin, C. R. J. Electrochem. SOC.1992, 739, 2530-2537. Parthasarathy, A.; Srlnivasan, S.; Appleby, A. J.; Martin, C. R. J. Electroanal. Chem. 1992, 339, 101-121. Urlbe, F. A.; SDringer. T. E.; Gottesfeid, S. J. Electrochem. Soc.1992. 139, 765-773. Amadeili, R.; DeBattisti, A.; Enea, 0. J. Electroanel. Chem. 1992, 339, 85-100. Liu, R.; Her, W.-H.; Fedkiw, P. S. J. Electrochem. Soc. 1982, 739, 15-23. Liu, R.; Fedkiw, P. S. J. Electrochem. Soc. 1982, 739, 3514-3523. Meli,G.;Leger, J.-M.; Lamy, C.; Durand, R. J. Appl. Electrochem. 1993, 234, 197-202. Inaba, M.; Hlnatsu, J. T.; Oeuml, 2.;Takehara. 2. J. Electrochem. SOC. 1993, 740, 706-711. Van Ryswyk, H.; Kim, C. H.; Staley, T. A. J. Electroanal. Chem. 1992, 325 - --, 351-357 -- . -- .. Ugo, P.; Ballarin, B.; Danieie, S.; Mazzocchin, G. A. J. Elechoanal. Chem. 1992, 324. 145-159. Audebert, P.; Divisia-Blohorn,B.; Aldebert, P.; Michalak, F. J. Eleciraanal. Chem. 1992, 322, 301-309. Toniolo, R.; BontemDeili. G.; Schiavon. G.; Zotti, G. J. Electroanel. Chem. 1993, 356, 67-80.’ Schiavon, G.; Zotti, G.; Toniolo, R.; Bontempelli, G. Anal. Chim. Acta 1892, 264, 221-228. Xu, M.; Horsthemke, W.; Schell, M. Electrochim. Acta 1983, 38, 919925. diCastro-Martins, S.; Khouzani, S.; Tuel, A.; Taarit, Y. B.; El Murr, N.; Sellami, A. J. Electroanel. Chem. 1993, 350, 15-28. Bedloui, F.; DeBoysson, E.; Devynck, J.; Balkus, K. J., Jr. J. Chem. SOC., Faraday Trans. 1991, 87, 3831-3834. Baker, M. D.; Senaratne, C.; Zhang, J. J. Chem. Soc., Faraday Trans. 1892, 88, 3167-3192. Petridis, D.; Falaras, P.; Plnnavaia. T. J. Inorg. Chem. 1992, 37,35303533 Brahlmi, B.; Labbe, P.; Reverdy. G. Langmuir 1982, 8, 1908-1918. Fitch, A.; Lee, S. A. J. Elechoanal. Chem. 1993, 344, 45-59. Kaviratna, P. Des.; Pinnavaia, T. J. J. Electroanal. Chem. 1992, 332, 135-145. Rong, D.; Mallouk, T. E. Inorg. Chem. 1993, 32, 1454-1459. Kutner, W. flectrochlm. Acta 1992, 37, 1109-1117. Kutner, W.; Dobihofer, K. J. Electroanal. Chem. 1992, 326, 139-160. Lepretre, J.-C.; Salnt-Aman, E.; Utilie, J.-P. J. Electroanal. Chem. 1993, 347, 465-470. Limoges, B.; Degrand, C.; Brossier, P.; Blankespoor, R. L. Anal. Chem. 1993, 65, 1054-1060. La Salle, A. L. G.; Limoges, B.; Anizon, J. Y.; Degrand. C.; Brossier, P. J. flectroanal. Chem. 1893, 350, 329-335. Wang, E.; Liu, A. Microchem. J. 1991, 44, 327-334. Gorskl, W.; Cox, J. A. Anal. Chem. 1992. 64, 2706-2710. Lorenzo, E.; AbruRa, H. D. J. flectroanal. Chem. 1992, 328, 111-125. Tleman, R. S.; Heineman, W. R. Anal. Le??.1992, 25, 807-819. Huang, J.; Wrighton, M. S. Anal. Chem. 1993, 65. 2740-2746. Mao, H.; Pickup, P. G. J. Phys. Chem. 1992, 96, 5604-5610. ai, 2.; Pickup, P. G. J. Electroanal. Chem. 1993, 355. 133-146. Basak, S.; Bose, C. S. C.; Rajeshwar, K. Anal. Chem. 1992, 64, 16131818.
Analytical Chemistry, Vol. 66,No. 12, June 15, 1994
419R
(F130) Yano, J.; Shimoyama, A.; Ogura, K. J. Chem. Soc., Faraday Trans. 1992. 88. ~~, 2523-2527. (F131) Bose, C. S. C.; Basak. S.; Rajeshwar, K. J. Phys. Chem. 1992, 96, 9899-9906. (F132) Chesher, D. A,; Christensen, P. A,; Hamnett, A. J. Chem. Soc.. Faraday Trans. 1993, 89, 303-309. (F133) Pyo, M.; Reynolds, J. R . J. Chem. Soc., Chem. Commun. 1993, 158260. (F134) Yue, J.; Epstein, A. J. J. Chem. Soc., Chem. Commun. 1992, 15401542. (F135) Duffitt, G. L.; Pickup, P. G. J. Chem. Soc., Faraday Trans. 1992, 88, 14 17- 1423. (F136) Schmidt, V. M.; Barbero, C.; Kotz, R. J. Electroanal. Chem. 1993, 352, 30 1-307. (F137) Novak, P.; Kotz, R.; Haas, 0. J. Electrochem. SOC.1993, 140, 37-40. (F138) Barbero, C.; Miras, M. C.; Kotz. R. flectrochlm. Acta 1992, 37,429437. (F139) Chen, C. C.; Wei, C.; Rajeshwar, K. Anal. Chem. 1993,65,2437-2442. (F140) Li, Y.; Dong, S. J. Chem. Soc., Chem. Commun. 1992, 827-828. (F141) Hepel, M.; Seymour, E.; Yogev, D.; Fendier, J. H. Chem. Mater. 1992, 4, 209-216. (F142) Deronizier, A.; Marques, M.J. J. Electroanal. Chem. 1992, 334,247261. (F143) Wooster, T. T.; Watanabe, M.; Murray, R. W. J. Phys. Chem. 1992, 96, 5886-5893. (F144) Watanabe, M.; Nagasaka, H.; Sanui, K.; Ogata, N.; Murray, R. W. Electrochim. Acta 1992, 37, 1521-1523. (F145) Baril, D.; Chabre, Y.; Armand, M. 9. J. Electrochem. SOC.1993, 140, 2687-2690. (F146) Che, G.; Dong, S. Electrochim. Acta 1993, 38,2315-2319. (F147) Third International Symposium on Polymer flectrolytes; Armand, M., Gandini, A., Eds. Electrochim. Acta 1992, 37,1469-1745. (F148) Nishihara. H.: Ohta, M.; Aramaki. K. J. Chem. SOC.,Faraday Trans. 1992, 88,627-831. (F149) Shi, G.: Xue, G.;Wu, Z.; Shen, 8. J. Electroanal. Chem. 1992, 338, 352-257. (F150) Velazquez, C. S.;Hutchison. J. E.; Murray, R . W. J. Am. Chem. SOC. 1993, 115, 7896-7897. (F151) Sullenberger, E. F.; Michael, A. C. Anal. Chem. 1993, 65,2304-2310. (F152) Turyan, I.; Mandler, D. Nature 1993, 362,703-704. (F153) Saiamon, Z.; Tollin, G. J. flectroanal. Chem. 1992, 342,381-391. (F154) Nelson, A. J. Electroanal. Chem. 1992, 335,327-343. (F155) Rojas, M. T.; Han, M.; Kalfer, A. E. Langmulr 1992, 8, 1627-1632. (F156) Doyle, M.; Fuller, T. F.; Newman, J. J. Electrochem. SOC.1993, 140, 1526-1533. (F157) Nahir, T. M.; Buck, R . P. J. Electroanal. Chem. 1992, 341, 1-14. (F158) Albagli, D.; Bazan, G.; Wrighton M. S.; Schrock, R. R . J. Am. Chem. SOC.1992, 114, 4150-4158. (F159) Nauven. M. T.: Diaz, A. F.; Dement'ev. V. V.; Pannell, K. H. Chem. Miter. 1993, 5, 1369-1394. (F160) Ikeda, S.; Oyama, N. Anal. Chem. 1993, 65,1910-1915. (F161) Oyama,N.;Tatsuma,T.;Takahashi.K.J. Phys.Chem. 1993,97,1050410508. (F162) Segawa, H.; Nakayama,N.; Shimidzu, T. J. Chem. Soc., Chem. Commun. 1992, 784-786. (F163) Deronzier, A,; Devaux, R.; Limosin, D.; Latour. J.-M. J. Electroanal. Chem. 1992, 324,325-337. a-Blohorn, 9.; Lapkowski, M.; Kern, J.-M.; Sauvage, J.-P. J. Am. Chem. SOC. 1992, 114, 5966-5994. (F165) Pickett, C. J.; Ryder. K. S.; Moutet, J.4. J. Chem. SOC.,Chem. Commun. 1992, 694-697. (F166) Bommarito, S. L.; Lowery-Bretz, S. P.; Abruiia. H. D. Inorg. Chem. 1992, 31,502-507. (F167) Bommarito, S . L.; Lowery-Bretz, S. P.; Abrufia, H. D. Inorg. Chem. 1992, 31,495-502. (F168) Subramanian, P.; Zhang, H.-T.; Hupp, J. T. Inorg. Chem. 1992, 31, 1540- 1542. (F169) Hable, C. T.; Crooks. R. M.; Valentine, J. R.; Giasson, R.; Wrighton, M. S. J. Phys. Chem. 1993, 97,6060-6065. (F170) Hatozaki. 0.:Ohsaka, T.; Oyama, N. J. Phys. Chem. 1992, 96,1049210497. (F 17 1) Katz, E.; delacey, A. L.; Fierro, J. L. G.; Palacios, J. M.; Fernandez, V. M. J. Electroanal. Chem. 1993, 358,247-259. (F172) Katz, E.; delacey, A. L;Fernandez, V. M. J. Electroanal. Chem. 1993, 358,261-272. (F173) Huang. S.; Song, X.; Lin, H.; Yu, R. Mlkrochim. Acta 1992, 107,27-36. (F174) Gache, Y.; Simonet, J. J. Chlm. Phys. Phys.-Chlm. Blol. 1992,89, 10271035. (F175) Horak, V.; Weeks, G. Bloorg. Chem. 1993, 21, 24-33. (F176) Bartlett, P. N.; Dawson. D. H.; Farrington, J. J. Chem. Soc., Faraday Trans. 1992, 88,2685-2695. (F177) Thobie-Gautier, C.; Gorgues, A.; Jubauit, M.; Roncali, J. Macromolecules 1993, 26,4094-4099. (F178) Fourmigue, M.; Johannsen, I.; Boubekeur, K.; Nelson, C.; Batail, P. J. Am. Chem. SOC.1993, 115, 3752-3759. (F179) Katz, E. Y.; Borovkov, V. V.; Evstigneera, R. P. J. flectroanal. Chem. 1992, 326,197-212. (F180) Albagli, D.; Bazan, G. C.; Schrock, R. R.; Wrighton. M. S. J. Am. Chem. SOC. 1993, 115, 7326-7334. (F181) Stilwell, D. E.; Park, K. H.; Miles, M. H. J. Appl. Electrochem. 1992, 22, 325-331, (F182) Moon, S.6.; Xidis, A.; Neff. V. D.J. Phys. Chem. 1993, 97, 1634-1638. (F183) Kuiesza, P. J.; Chelmecki. G.;Gaiadyk, B. J. flectroanai. Chem. 1993, 34% 417-423. (F184) Jiang, M.; Wang, M.; Zhou, X. Chem. Lett. 1992, 1709-1712. ~
42QR
Analytical Chemistry, Vol. 66, No. 12,June 15, 1994
(F185) Luangdilok, C. H.; Arent, D. J.; Bocarsly, A. 9.; Wood, R. Langmulr 1992. 8. 650-657. (F186) Zhou, J.; Wang, E. J. Electroanal. Chem. 1992, 331, 1029-1043. (F187) Pllchon, V.; Besbes, S. flectrochim. Acta 1992, 37,501-506. (F188) Xidis, A.; Neff, V. D. J. Electrochem. SOC. 1991, 138,3637-3642. (F189) Kondratev,V. V.;Vlnokurov, I.A.;Bertsev,V.V.;Khakin. S.Y.;Zelenina, 0. M. Elektrokhlmiya 1992, 28,74-80. (F190) Yoneyama. H.; Takahashi. N.; Kuwabata, S. J. Chem. SOC.,Chem. Commun. 1992, 716-717. (F191) Kuwabata. S.; Takahashi, N.; Hirao, S.; Yoneyama. H. Chem. Mater. 1993. ._, 5 437-441. . (F192) Collomb-Dunand-Sauthier. M.-N.; Deronzier, A.; Zlessel, R. J. Phys. Chem. 1993, 97, 5973-5979. (F193) Kuwabata, S.; Mitsui, K.; Yoneyama, H. J. Electrochem. SOC.1992, 139. 1824-1630. (F194) Argiis. P.; Srinivas, R . A.; Carls, J. C.; Heller, A. J. flectrochem. SOC. 1992, 139,2889-2894. (F195) GouM, S.; Gray, K. H.; Linton, R. W.; Meyer, T. J. Inorg. Chem. 1992, 31,5521-5525. (F196) Sawai, T.; Yamazaki, S.;Ishigami, Y.; Ikariyama, Y.; Alzawa, M. J. Electroanal. Chem. 1992, 322, 1-7. (F197) Miyasaka, T.; Koyama, K.; Itoh, I.Science 1992, 255,342. (F198) Wollman, E. W.; Frisbie, C. D.; Wrighton, M. S. Langmulr 1993, 9. 15 17- 1520. (F199) Nishizawa, M.; Miwa, Y.; Matsue, T.; Uchida, I.J. Electrochem. SOC. 1993, 140, 1650-1655. (F200) Nishizawa, M.; Shibuya, M.; Sawaguchl, T.; Matsue. T.; Uchida, I.J. Phys. Chem. 1991, 95, 9042-9044. (F201) Fuiii. M.: Arii. K.: Yoshino. K. J. Electrochem. SOC.1993.. 140.. 18381842. (F202) Jin, J.-Y.; Teramae. N.: Haraguchi, H. Chem. Left. 1993, 101-104. (F203) Rodriguez-Mendez. M. L.: Aroca, R.; DeSaja, J. A. Chem. Mater. 1992, 4, 1017-1020. (F204) Toshima, N.; Kawamura, S.;Tominaga, T. Chem. Len. 1993, 12991302. (F205) Saika, T.; Iyoda. T.; Shimidzu. T. Bull. Chem. SOC. Jpn. 1993, 66, 2054-2060. (F206) Nawa, K.; Miyawaki, K.; Imae, I.; Noma, N.; Shirota, Y. J. Mater. Chem. 1993, 3, 113-1 14. (F207) Kanbara, T.; Yamamoto, T. Macromolecules 1993, 26, 1975-1979. (F208) Shen, P. K.; Huang. H. T.; Tseung, A. C. C. J. Electrochem. SOC.1992, 139,1840-1845. (F209) Yoneyama, H.; Hirao, S.; Kuwabata, S. J. flectrochem. SOC. 1992, 139, 3141-3146. (F210) Read, D. C.; Christensen. P. A.; Hamnett, A. J. Electroanal. Chem. 1993, 354,325-329. (F211) Siekierski, M.; Plocharski, J.; Catellanl, M.; Destri, S. Springer Ser. Solic%State Scl. 1992, 107, 341-345. (F212) Leventis, N.; Chung. Y. C. Chem. Mater. 1992, 4, 1415-1422. (F213) Bradley, D. D. C. Synth. Met. 1993, 54, 401-415. (F214) Karg, S.; Riess, W.; Dyakonov, V.; Schwoerer, M. Synth. Met. 1993, 54, 427-433. (F215) Gustafsson, G.; Cao, Y.; Treacy, G. M.; Klavetter, F.; Colaneri, N.; Heeger, A. J. Nature 1992, 357,477-479. (F216) Greenham, N. C.; Morattl, S. C.; Bradley, D. D. C.; Friend, R. H.; Holmes, A. 9. Nature 1993, 365,628-630. (F217) Yamamoto, T.; Wakayama, H.; Fukuda, T.; Kanbara, T. J. Phys. Chem. 1992, 96.8677-6679. (F218) Xu, 8.; Holdcroft, S. Macromolecules 1993, 26,4457-4460. (F219) Andrieux, C. P.; Audebert, P.; Hapolt, P.; Saveant, J.-M. J. phys. Chem. 1991, 95, 10158-10164. (F220) Hoier, S. N.; Park, S.-M. J. Electrochem. SOC.1993, 140, 2454-2463. (F221) Raymond, D. E.; Harrison, D. J. J. Electroanal. Chem. 1993, 355,115131. (F222) Qiu, Y.J.; Reynolds, J. R. J. Polym. Sci. Part A: Polym. Chem. 1992, 30,1315. (F223) Mendes Viegas, M. F.; Genies, E. M.; Fouletier, M.; Vieil, E. flectrochim. Acta 1992, 37,513-522. (F224) Lukkari, J.; Aianko, M.; Heikkila, L.; Laiho, R.; Kankare, J. Chem. Mater. 1993, 5, 289-296. (F225) Tuomala, R.; Ristimaki, S.; Kankare, J. Synth. Met. 1992, 47,217-231. (F226) Li, F.; Albery, W. J. €/8ctrochim. Acta 1992, 37,393-401. (F227) Li. F. 6.; Albery, W. J. Langmulr 1992, 8, 1645-1653. (F228) Jeon, D.; Kim, J.; Gallagher, M. C.; Willis, R. F. Science 1992, 256, 1662- 1663. (F229) Wei, Y.; Tian, J. Macromolecules 1993, 26,457-463. (F230) Genies, E. M.; N d l , P. Synth. Met. 1992, 46, 285-292. (F231) Liang, W.; Lei. J.; Martin. C. R. Synth. Met. 1992, 52,227-239. (F232) Kankare, J.; Vuorinen. V.; Alanko, M.; Lukkari, J. J. Chem. SOC.,Chem. Commun. 1993, 241-242. (F233) Kim, Y.-T.; Yang, H.; Bard, A. J. J. Electrochem. SOC.1991, 738,L71L74. (F234) Yang, H.; Bard, A. J. J. Nectroanal. Chem. 1992, 339, 423-449. (F235) Sabatani, E.; Redondo. A.; Rishpon, J.; Rudge. A,; Rubinstein, I.; Gottesfeld, S. J. Chem. Soc.. Faraday Trans. 1993, 89, 267-294. (F236) Michaelson, J. C.; McEvoy, A. J.; Kuramoto, N. React. Polym. 1992, 17, 197-206. (F237) Osawa. S.; Ito, M.; Tanaka, K.; Kuwano, J. J, Polym. Scl.,Pt.B: Polym. Phys. 1992, 30, 19-24. (F238) Osaka, T.; Momma. T.; Kanagawa, H. Chem. Left. 1993, 649-652. (F239) Witkowski, A.; Brajther-Toth, A. Anal. Chem. 1992, 64, 635-641. (F240) Park, D.-S.; Shlm, Y.-B.; Park, S.-M. J. Electrochem. SOC.19g3, 140, 2749-2752. (F241) Qi, Z.; Pickup. P. G. J. Chem. Soc.. Chem. Commun. 1992,1675-1676. (F242) Beck, F.; Oberst, M. J. Appl. Electrochem. 1992, 22,332-340.
-.
(F243) Cienles. E. M.; MarchesbHo, M.; Bidan, G. Electrochlm. Acta 1992,37. 1015-1020. (F244) LI, S.; Macosko, C. W.; White, H. S. Sclence 1993. 259, 957-960. (F245) Li, S.; White, H. S. J. Electrochem. Soc.1993, 740, 2473-2476. (F246) Trlvedi, D. C.; Dhawan, S. K. J. Chem. Mater. 1992, 1091-1096. (F247) Torres, W.; Fox, M. A. Chem. Meter. 1992, 4, 583-588. (F248) Yamamoto, K.; Park, Y. S.; Takeoka, S.; Tsuchida, E. J. Electroanel. Chem. 1991, 378, 171-181. (F249) Park, Y.; Yamamoto. K.; Takeoka, S.; Tsuchida, E. Bull. Chem. SOC. Jpn. 1992, 65, 1860-1865. (F250) Park, Y . 6 ; Ohta, T.; Takeoka, S.; Yamamoto, K.; Tsuchida. E. Bull. Chem. SOC.Jpn. 1993, 66, 2449-2451. (F251) Miller, L. L.; Zhong, C.J.; Kasai, P. J. Am. Chem. Soc. 1983, 115, 5982-5990. (F252) Fabre, B.; Bidan, G.; Fichou, D. J. Chlm. Phys. Phys.-Chlm. Bbl. 1992, 89, 1053-1062. (F253) Mattoso, L. H. C.; Buihoes, L. 0. S. Synth. Met. 1992, 52, 171-181. (F254) Ocon, P.; Herrasti, P. New J. Chem. 1992, 76, 501-504. (F255) Levi. M. D.; Piserevskaya, E. Y.; Moiodkina, E. B.; Daniiov, A. I . J. Chem. Soc., Chem. Commun. 1992, 149-151. (F258) Kobryanskii, V. M.; Arnautov, S. A. Mekromol. Chem. 1992, 193,453463. (F257) Shimura, T.; Funaki, H.; Nishihara,H.; Aramaki, K.; Ohsawa, T.; Yoshino, K. Chem. Lett. 1992, 457-460. (F258) Morita, M.; Komaguchi, K.; Tsutsumi, H.; Matsuda, Y. Electrochim. Acta 1992. 37, 1093-1099. (F259) Goklenberg, L. M.; Aeiyach, S.; Lacaze, P. C. J. Electfoanal. Chem. 1992, 327, 173-184. (F260) Goldenberg, L. M.; Aeiyach, S.; Lacaze, P. C. J. Electroanel. Chem. 1992, 335, 151-161. (F261) Froyer, 0.; Olilvier, G.; Chevrot, C.; Slove, A. J. Electroanel. Chem. 1992, 327, 159-171. (F262) Phani, K. L. N.; Pitchumani, S.; Ravichandran, S.; Selvan, S.T.; Bharathey, S. J. Chem. Soc., Chem. Commun. 1933, 179-161. (F263) Jehouiet, C.; Obeng, Y. S.; Kim, Y-T.; Zhou, F.; Bard, A. J. J. Am. Chem. SOC. 1992, 114, 4237-4247. (F264) Koh, W.; Dubois, D.; Kutner, W.; Jones, M. T.; Kadish, K. M. J. Phys. Chem. 1992, 96, 4163-4165. (F265) Zhou, F.; Yen, S.-L.; Jehoulet, C.; Laude, D. A., Jr.; Guan, 2.; Bard, A. J. J. Phys. Chem. 1992, 96, 4160-4162. (F266) Hili, M. G.; Mann, K. R.; Miller, L. L.; Penneau, J.-F. J. Am. Chem. Soc. 1992, 114, 2728-2730. (F267) Hill. M. 0.; Penneau, J.-F.; Zinger, B.; Mann, K. R.; Miller, L. L. Chem. Meter. 1992, 4, 1106-1113. (F268) Bliuerle, P.; Segeibacher, U.; Maier, A.; Mehring, M. J. Am. Chem. Soc. 1893, 115, 10217-10223. (F269) Zotti, G.; Schiavon, G.; Berlin, A.; Pagani, G. Chem. Mater. 1993, 5, 620-624. (F270) Biiuerie, P.; Segeibacher, U.; Gaudl, K.4.; Hutlenlocher, D.; Mehring. M. Angew. Chem., Int. Ed. Engl. 1993, 32, 76-78. (F271) Xu, 2.4.;Horowitz, G. J. Elechoanal. Chem. 1992, 335, 123-134. (F272) Quay. J.; Diaz, A.; Wu, R.; Tour, J. M.; Dao, L. H. Chem. Mater. 1992. 4, 255-258. (F273) Guay,J.;Kasai.P.;Diaz,A.;Wu,R.;Tour,J.M.;Dao,L.H.Chem.Mater. 1992, 4, 1097-1105. (F274) Guay, J.; Dlaz, A.; Wu, R.; Tour, J. M. J. Am. Chem. Soc. 1993, 715. 1869-1874. (F275) Jozefiak, T. H.; Ginsburg, E. J.; Gorman, C. B.; Grubbs, R. H.; Lewis, N. S. J. Am. Chem. Soc. 1993, 115, 4705-4713. (F276) Duffm, G. L.; Pickup, P. G. J. Phys. Chem. 1991, 95, 9634-9635 (F277) Son, Y.; Rajeshwar, K. J. Chem. Soc., Faraday Trans. 1992, 88, 605610. (F278) Van Dyke, L. S.; Kuwabata, S.; Martin, C. R. J. Electrochem.Soc. 1993, 140, 2754-2759. (F279) Hoier, S. N.; Park, S.-M. J. Phys. Chem. 1992, 96, 5188-5193. (F280) Tolbert, L. M. Acc. Chem. Res. 1992, 25, 561-566. (F281) Cain, S. R.; Gale, D. C.; Gaudieiio, J. G. J. Phys. Chem. 1991, 95, 9584-9589. (F282) Vorotyntsev, M. A.; Daikhin, L. I.; Levi, M. D. J. Electroanal. Chem. 1992, 332, 213-235. (F283) Doblhofer, K. J. Nectroanal. Chem. 1992. 331, 1015-1027. (F284) Mafe, S.; Manzanares, J. A.; Reiss, H. J. Chem. Phys. 1993, 98, 24082410. (F285) Chertier, P.; Mattes, B.; Reiss, H. J. Phys. Chem. 1992, 96,3556-3560. (F286) Asturlas, G. E.; Jang, 0.-W.; MacDiarmid, A. 0.; Doblhofer, K.; Zhong, C. Ber. Bunsenges. Phys. Chem. 1991, 95. 1381-1384. (F287) Aoki, K. J. Electroanal. Chem. 1992, 334, 279-290. (F288) Daikhin, L. 1.; Levin, M. D. J. Chem. Soc., Faraday Trans. 1992, 88, 1023- 1026. (F289) Bacskai, J.; Kertesz, V.; Inzeit, G. Electrochim. Acta 1993, 38, 393397. (F290) Santhanam, K. S. V.; Gupta, N. Trends Po/ym. Sci. 1993, 1, 284-289. (F291) Novak, P.; Vieistich, W. Collect. Czech. Chem. Commun. 1992, 57, 339-348. (F292) Desihrestro, J.; Scheltele, W.: Haas, 0. J. Electroanel. Chem. 1992, 739, 2727-2736. (F293) Velayutham, D.; Noel, M. Talenta 1992, 39, 481-486. (F294) Kostecki, R.; Ulmann, M.; Augustynski, J.; Strike, D. J.; Koudeika-Hep, M. J. Phys. Chem. 1993, 97, 8113-8115. (F295) Leone, A.; Marino, W.; Scharifker, B. R. J. Electrochem. SOC. 1992, 139, 438-443. (F296) Bose, C. S. C.; Rajeshwar, K. J. Electroanal. Chem. 1992, 333, 235256
(F297)
Ch&,
C. C.; Bose, C. S. C.; Rajeshwar, K. J. Electroanel. Chem. 1993,
350, 161-178.
(F298) Beck, F.; Dahihaus, M. J. Appl. Electrochem. 1993, 23, 781-789.
(F299) Beck, F.; Dahihaus. M.; Zahedl, N. Electrochim. Acta 1992, 37, 12851272. (F300) Lawson, D. R.; Liang, W.; Martin, C. R. Chem. Meter. 1993,5400-402. (F301) Fabrizio, M.; Furlanetto, F.; Mengoli, G.; Musiani, M. M.; Paoiucci, F. J. Electroanel. Chem. 1992. 323, 197-212. (F302) Otero. T. F.; Angulo, E.; Rodrlquez, J.; Santamaria, C. J. Ektroanal. Chem. 1992, 341, 369-375. (F303) Pel, Q.; Inganas. 0. J. Phys. Chem. 1992, 96. 10507-10514. (F304) Pel, 0.; Inganas. 0. J. Phys. Chem. 1993, 97, 6034-6041. (F305) Herod, T. E.; Schlenoff, J. 8. Chem. Meter. 1993, 5, 951-955. (F306) Aoki, K.; Aramoto, T.; Hoshino, Y. J. Electroanal. Chem. 1992, 340. 127-135. (F307) McCoy, C. H.; Wrighton, M. S. Chem. Meter. 1993, 5, 914-916. (F308) Fox, M. A. Acc. Chem. Res. 1992, 25, 569-574. (F309) Buck, R. P.; SurrMge, N. A.; Murray, R. W. J. Electrochem. Soc. 1992, 139. 136-144. (F310) Han; D.; Shimada, S.; Murray, R. W.; Silve, M. phys. Rev. B. Condens. Matter 1992. 45. 9436-9438. (F311) Nishihara, H.; Akasaka, M.; Tateishi, M.; Arameki, K. Chem. Lett. 1992. 206 1-2064. (F312) Gottesfeid, S.; Uribe. F. A.; Armes. S. P. J. Electrochem. SOC.1992,
139, L14-Ll5. (F313) Chin, H.-T.; Lin, J.4. J. Meter. Scl. 1992, 27, 319-327. (F314) Smith, C. P.; White, H. S. Anal. Chem. 1992, 64, 2398-2405. (F315) Pope, J. M.; Tan, 2.;Kimbrell, S.; Buttry, D. A. J. Am. Chem. Soc. 1992. 114, 10085-10086. (F316) DeLong, H. C.; Buttry, D. A. Langmulr 1992, 8, 2491-2496. (F317) Kitamura, F.; Ohsaka, T.; Tokuda, K. J. Electroanal. Chem. 1993, 347, 37 1-381. (F318) Creager, S. E.; Weber, K. Langmulr 1993, 9, 844-850. (F319) Becka, A. M.; Miller, C. J. J. Phys. Chem. 1992, 96, 2657-2668. (F320) Takehara, K.; Hiroyuki, T.; Ide, Y. J. Coliohj Interface Scl. 1993, 156, 274-278. (F321) Finklea, H. 0.; Hansbw, D. D. J. Am. Chem. Soc. 1992, 114,31733181. (F322) Curtin, L. s.; Peck, S. R.; Tender, L. M.; Murray, R. W.; Rowe, G. K.; Creager, S. E. Anal. Chem. 1993, 65, 386-392. (F323) Hong, H A . ; Mailouk, T. E. Langmulr 1991. 7, 2362-2369. (F324) Obeng,Y. S.;Laing,M.E.; Friedli,A.C.;Yang,H.C.; Wang,D.;Thuistrup, E. W.; Bard, A. J.; Michl, J. J. Am. Chem. Soc. 1992, 174, 9943-9952. (F325) Finklea, H. 0.; Hanshew, D. D. J. Electroanal. Chem. 1993, 347, 327340. (F326) Finklea, H. 0.; Ravenscroft, M. S.; Snider, D. A. Langmulr 1993, 9, 223-227. (F327) Doblhofer, K.; Figura, J.; Fuhrhop, J.-H. Langmuir 1992,8, 1611-1816. (F328) Cheng, Q.; Braher-Toth, A. Anal. Chem. 1992, 64, 1998-2000. (F329) Xie, Y.; Dong, S. J. Chem. Soc.,Faraday Trans. 1992, 88.2697-2700. (F330) Wang, J.; Frostman, L. M.; Ward, M. D. J. Phys. Chem. 1992, 96, 5224-5228. (F331) Maiem, F.; Mandier, D. Anal. Chem. 1993, 65, 37-41. (F332) Smith, C. P.; White, H. S. Langmulr 1993, 9, 1-3. (F333) Redepenning, J.; Tunison, H. M.; Finklea, H. 0. Langmulrl993, 9, 14041407. (F334) Acevedo, D.; Abruira, H. D. J. Phys. Chem. 1991, 95, 9590-9594. (F335) Rowe, G. K.; Creager, S. E. Langmuir 1991, 7, 2307-2312. (F336) Lindholm-Sethson, B.; Orr, J. T.; Ma@, M. Langmulr 1993, 9, 21812167. (F337) Charych, D. H.; Goss, C. A.; Majda. M. J. Electroanal. Chem. 1992.323, 339-345. (F338) Katz, E.; Itzhak, N.; Willner, I.Langmulr 1993, 9, 1392-1396. (F339) Bilewicz, R.; Ma@, M. Langmulr 1991, 7, 2794-2802. (F340) Waiczak, M. M.; Popenoe, D. D.; Delnhammer. R. S.; Lamp, B. D.; Chung, C.; Porter, M. D. Langmulr 1991, 7, 2687-2693. (F341) Weisshaar, D. E.; Lamp, B. D.; Porter, M. D. J. Am. Chem. Soc.1982, 114, 5860-5862. (F342) Chailapakui. 0.; Crooks, R. M. Langmulr 1993, 9, 884-886. (F343) Odashima, K.; Kotato, M.; Sugawara, M.; Umezawa, Y. Anal. Chem. 1993, 65, 927-938. (F344) Takehara, K.; Yamada, S.; Ide, Y. J. Electroanal. Chem. 1992, 333, 339-344. (F345) Kim. Y. T.; Bard, A. J. Langmulr 1992, 8, 1096-1102. (F348) Katz, E.; Rikiin, A.; Willner, I.J. Electroanel. Chem. 1993, 354, 129144. (F347) Lu, T.; Zhang, L.; Gokei, 0. W.; Kaifer, A. E. J. Am. Chem. SOC.1993, 115, 2542-2543. (F348) Cammarata, V.; Atanososka, L.; Miller, L. L.; Kolaskie, C. J.; Stailman, B. J. Langmuk 1992, 8, 876-886. (F349) Kwan, V. W. S.;Cammarata, V.; Miller, L. L.; HHi, M. 0.; Mann, K. R. Langmulr 1992, 8, 3003-3007. (F350) Iwamoto, M.; Majima, Y.; Naruse, H.; Noguchi, T.; Fuwa, H. J. Chem. PhyS. 1991, 95, 8561-8567. (F351) Liu, Z.-F.; Hashimoto, K.; Fujishima, A. Chem. Phys. Lett. 1991, 785, 501-504. (F352) Llu. L F . ; Morigaki, K.; Hashimoto. K.: FuJishima.A. Anal. Chem. 1992, 64, 134-137. (F353) Morigaki, K.; Liu, 2. F.; Hashimoto, K.; Fujishima, A. Ber. Bunsenges. Phys. Chem. 1993, 97, 860-864. (F354) Liu, Z. F.; Morigaki, K.; Hashimoto, K.; Fujishima, A. J. Photochem. Photobiol. A 1992, 65, 285-292. (F355) Song, S.; Clark, R. A.; Bowden, E. F.; Tarlov. M. J. J. Phys. Chem. 1993, 97, 6564-6572. (F358) Collinson, M.; Bowden, E. F.; Tarlov, M. J. Langmuk 1892, 8, 12471250. (F357) Nakashima,N.;Abe,K.;Hbohashi,T.;Hamada,K.;Kunitake.M.;Manabe. 0. Chem. Lett. 1993. 1021-1024.
Analytical Chemistry, Vol. 66,No. 12, June 15, 1994
421R
(F358) Erabi, T.; Ozawa, S.;Hayase, S.; Wada, M. Chem. Lett. 1992, 211521 18. (F359) Kinnear, K. T.; Monbouquette, H. G. Langmuir 1993, 9, 2255-2257. (F360) Parpaleix, T.; Laval, J. M.; Majda, M.; Bourdlllon, C. Anal. Chem. 1992, 64, 641-646. (F361) Wlllner, I.; Katz, E.; Riklln, A.; Kasher. R. J. Am. Chem. SOC.1992, 114, 10965- 10966. (F362) Sato, Y.; Itoigawa, H.; Uosaki, K. Bull. Chem. SOC.Jpn. 1993, 66, 1032- 1037. (F363) Martin, A. S.; Sambies, J. R.; Ashwell, G. J. Phys. Rev. Lett. 1993, 70, 218. (F364) Ueyama, S . ;Wada, 0.; Miyamoto, M.; Kawakubo, H.; Inatomi, K.; Isoda, S. J. Eiectroanal. Chem. 1993, 347, 443-449. (F365) Liu, M. D.; Leaner, C. R.; Facci, J. S . J. Phys. Chem. 1992, 96, 28042811. Rusling, J. F. Langmuir1992, 8, 1633-1636. (F366) Sucheta, A.; uI Haque, I.; (F367) Nelson, A. J. Chem. SOC.,Faraay Trans. 1993, 89, 3081-3090. (F368) Abbott, A. P.; Gounili, G.; Bobbltt, J. M.; Rusiing, J. F.; Kumosinskl. T. F. J. Phys. Chem. 1992, 96, 11091-11095. (F369) Li. J.; Kaifer, A. E. Langmuir 1993, 9, 591-596. (F370) (F371) Petty, M.; Lovett, D. R.; Miller, J.; Silver, J. J. Mater. Chem. 1991, 1, 971-976. (F372) Engelman, E. E.; Evans, D. H. Langmuir 1992, 8, 1637-1644. (F373) Becka, A. M.; Miller, C. J. J. Phys. Chem. 1993, 97, 6233-6239. (F374) Rillema, D. P.; Edwards, A. K.; Perine. S. C.; Crumbliss, A. L. Inorg. Chem. 1991, 30, 4421-4425. (F375) Dvorak, 0.; DeArmond, M. K. J. Phys. Chem. 1993, 97, 2646-2648. (F376) Iroh, J. 0.; Bell, J. P.; Scola, D. A. J. Appl. Polym. Sci. 1991, 43, 2237-2247. (F377) Osada, Y.; Okuzaki, H.; Hori, H. Nature 1992, 355, 242-244. (F378) Wang, J.; Golden, T.; Lin, Y.; Angnes, L. J. Electroanal. Chem. 1992, 333, 65-75. (F379) Christie, I.M.;Treloar, P. H., Vadgama, P. Anal. Cbim. Acta 1992,269, 65-73.
G. BIOELECTROCHEMISTRY Smyth, W. F. Voltammetrlc Determination of Molecules of Biologibal Significance; John Wiley & Sons: England, 1992. Eds. Redox Mechanisms and Interfacial Schultz, F. A., Taniguchi, I., Properties of Molecules of Bioioglcai Importance, Proceedings; The Electrochemical Society: Pennlngton, NJ, 1993; Vol. 93-1 1. Paulsen, K. E.; Stankovich, M. T.; Orville, A.M. MethodsEnzymol. 1993, 227, 396-411. Armstrong, F. A.; Butt, J. N.; Sucheta, A. MethodsEnzymol. 1993, 227, 479-500. Hill, H. A. 0.; Hunt, N. I.Methods Enzymoi. 1093, 227, 501-521. Cox, J. A.; Przyjazny, A. TrAC, TrendsAnal. Chem. 1992, 71,298-302. Ewing, A. G.; Strein, T. G.; Lau, Y. Y. Acc. Chem. Res.1992, 25, 440447. Kauffmann, J. M.; Vir& J. C. Anal. Chim. Acta 1993, 273, 329-334. Voik, K. J.; Yost, R. A.; Brajtertoth, A. Anal. Chem. 1992, 64. A21. Ikeda, T. Bull. Electrochem. 1992, 8, 145-159. Bourdillon, C. Ann. N.Y. Acad. Sci. 1992, 672, 195-212. Gorton, L.; Jonsson-Pettersson, G.; Csoregl, E.; Johansson, K.; Dominguez, E.; Markovarga, G. Analyst 1992, 117, 1235-1241. Heller, A. J. Phys. Chem. 1992, 96, 3579-3587. Boguslavsky, L.; Hale, P. D.; Geng, L.; Skothelm, T. A,; Lee, H. S. Solid State Ionics 1993, 60, 189-197. Wilson, R.; Turner, A. P. F. Biosens. Bimlectron. 1992, 7, 165-185. Ivnitskii, D, M.; Kurochkln, I. N.; Varfolomeev, S. D. 2. Anal. Khim. 1991, 26, 1462-1479. Green, M. J. Analyst 1991. 116, 1217-1220. HildRch, P. I.; Turner, A. P. F., Ed. Advances in Biosensors; 1992; Vol. 2. Nakamura, M., Kasahara, Y., Rechnitz, G. A., Eds. Immunochemical ~ III; Amerlcan Assays and Biosensor Technology for the 1 9 9 0 ~Part Society for Microbiology: Washington, DC, 1992. Wring, S.A.; Hart, J. P. Analyst 1992, 117, 1215-1229. Nikolells, D. P.; Krull, U. J. Electroanalysis 1993, 5, 539-545. Onova-Leitmannova,A.; Tien, H. T. Prog. Surf.Sci. 1992,4 1,337-445. Kuhr, W. G.; Barren, V. L.; Gagnon, M. R.; Hopper, P.; Pantano, P. Anal. Chem. 1993, 65, 617-622. Hale, P. D.; Lee, H. S.; Okamoto, Y. Anal. Lett. 1993, 26, 1073-1085. Kashlwagl, Y.; Osa, T. Chem. Lett. 1993, 677-680. Somasundrum, M.; Bannister, J. V. J. Chem. Soc., Chem. Commun. 1993, 1629-1631. Ohsaka, T.; Tanaka, K.; Tokuda, K. J. Chem. SOC.,Chem. Commun. 1903, 222-224. Beley, M.; Collin. J. P. J. Mol. Catal. 1993, 79, 133-140. Shimizu, Y.; Kitani, A.; Ito. S.; Sasaki, K. Denki Kagaku 1993, 61, 872-873. Cantet, J.; Bergei, A.; Comtat, M.; Seris, J. L. J. Mol. Catal. 1992, 73, 371-380. Xu. H. T.: Kltamura.. F.:. Ohsaka.. T.:. Tokuda. K. Denk; Kaoaku 1992. 60; 1068-1074. Allred, C. D.; Mccreery, R. L. Anal. Chem. 1992, 64, 444-448. Matysik, F. M.; Nagy, G.; Pungor, E. Anal. Chlm. Acta 1992,264. 177184. Malem, F.; Mandler, D. Anal. Chem. 1993, 65, 37-41. Vandeberg, P. J.; Johnson, D. C. Anal. Chem. 1993, 65, 2713-2718. Lacourse, W. R.; Johnson, D. C. Anal. Chem. 1993, 65, 50-55. Zhou. J. X.; Wang, E. J. Electroanel. Chem. 1992, 337, 1029-1043. Wang, E.; Liu, A. J. Electroanal. Chem 1991, 319, 217-225. (a) Zhao, S.S.;Lennox, R. E. J. Eiectroanal. Chem. 1993, 346, 161173. (b) Korell, U.; Lennox, R. B. Anal. Chem. 1992, 64, 147-151.
-
422R
Analytical Chemistty, Vol. 66, No. 72, June 75, 1994
(G40) (G41) (G42) (G43) (G44)
(G45) (G46) (G47) (G48)
Zhao, S. S.; Lennox, P. B. J. Electroanel. Chem. 1993, 346, 161-173. Tsai, H.; Weber, S. G. Anal. Chem. 1992, 64, 2897-2903. Malinski, T.; Taha, 2. Nature 1992, 358. 676-678. Nakamura, N.; Kohzuma, T.; Suzuki, S. Bull. Chem. Soc. Jpn. 1993, 66, 1289-1291. Nlu, J.; Dong, S. Electroanalysis 1093, 5, 571-574. Sagara, T.; Takagl, S.; Niki, K. J. Electroanel. Chem. 1993, 349, 159171. Emons, H.; Wittstock, G.; Vo!gt, 6.; Seidel, H. Fresenius J. Anal. Chem. 1992, 342, 737-739. Vehagen, M. F. J. M.; Hagen, W. R. J. Electroanal. Chem. 1992,334, 339-350. Takehara, K.; Takemura, H.; Ide, Y. J. ColloM InterfaceSci. 1993, 156, 274-278. Nakashima, N.; Masuyama, K.; MochMa, M.; Kunkake, M.; Manabe, 0. J. Electroanal. Chem. 1991, 379, 355-359. Mallik, 6.; Gani, D. J. Electroanal. Chem. 1992, 326, 37-49. Sagara, T.; Murakami, H.; Igarashi, S.;Sato, H.; Niki, K. Langmulr 1991. 7, 3190-3196. Wlide, C. P.; Ding, T. J. Electroanel. Chem. 1992, 327, 279-290. Zhou, C. L.; Ye, S.Y.; Klm, J. H.; Cotton, T. M.; Yu, X. J.; Lu, T. H.; Dong, S. J. J. Electroanal. Chem. 1991, 379, 71-83. Szucs, A.; HRchens, G. D.; Bockris, J. 0. M. Electrochim. Acta 1992, 37, 403-412. Mayne, A. J.; Cataidi, T. R. 1.; Knaii, J.; Avery, A. R.; Jones, T. S.; Plnhelro, L.; Hill, H. A. 0.; Brlggs, G. A. D.; Pethlca, J. 6.; Weinberg, W. H. Faraday Discuss. 1992, 199-212. Tominaga, M.; Hayashi, K.; Taniguchi, I.Anal. Sci. 1992, 8, 829-836. Haladjian, J.; Bruschi, M.; Nunzl, F.; Bianco, P. J. Necfroanal. Chem. 1993, 352, 329-335. Bond, A. M.; Hill, H. A. 0.; Komorskyiovric, S.;Lovrlc, M.; Mccarthy, M. E.; Psalti, J. S. M.; Walton, N. J. J. Phys. Chem. 1992, 96, 81008105. Nakashima, N.; Abe, K.; Hirohashl, T.; Hamada, K.; Kunkake, M.; Manabe, 0. Chem. Lett. 1993, 1021-1024. Salamon, 2.; Gleason, F. K.; Tollln, G. Arch. Blochem. Blophys. 1992, 299, 193-198. Taniguchi, I.; Kurihara, H.; Yoshida, K.; Tominaga, M.; Hawkrage, F. M. Denki Kagaku 1992, 60, 1043-1049. Daido, T.; Akalke, T. J. Electroanal. Chem. 1093, 344, 91-106. Taniguchi, 1.; Hayashi, K.; Tominaga, M.; Muraguchi, R.; Hlrose, A. Denki Kagaku 1993, 61, 774-775. Colllnson, M.; Bowden, E. F. Langmuir 1992, 8, 2552-2559. Ohtani, M.; Ikeda, 0. J. Elecfroanal. Chem. 1993, 354, 311-317. Dana, D.; Hill, H. A. 0.; Nakayama, H. J. Electroanai. Chem. 1992,324, 307-323. Buchi, F. N.; Bond, A. M.; Codd, R.; Huq, L.N.; Freeman, H. C. Inorg. Chem. 1992, 37, 5007-5014. Yuan, X.; Hawkridge. F. M.; Chlebowski, J. F. J. Electroanal. Chem. 1993, 350, 29-42; Barker, P. D.; Mauk, A. G. J. Am. Chem. Soc. 1902, 114,3619-3624. Bixler, J.; Bakker, G.; McLendon, G. J. Am. Chem. SOC. 1992, 114, 6938-6939. Hilgen-Willis, S.;Bowden, E. F.; Pieiak, G. J. J. Inorg. Biochem. 1993, 51. .. , 649-653. .. - -. Cruanes, M. T.; Rodgers, K. K.; Sligar, S . G. J. Am. Chem. SOC. 1992, 174. 9660-9661. Kohzuma, T.; Takase, S.; Shidara, S.; Suzuki, S . Chem. Lett. 1993, 149-152. Iwasakl, Y.; Suzuki, M.; Takeuchi, T.; Tamiya, E.; Karube, I.; Nishlyama, M.; Horlnouchl, S.;Beppu, T.; Kadoi, H.; Uchiyama. S.; Suzuki, S . Electroanalysis 1992, 4, 765-770. Erabi. T.; Ozawa, S.;Hayase, S . ; Wada, M. Chem. Lett. 1992, 21 1521 16. Legail, J.; Liu, M. Y.; Payne, W. J.; Moreno, C.; Costa, C.; Moura, I.; Vandijk, C.; Moura, J. J. G. Eur. J. Blochem. 1093, 272, 79-86. Iwasaki, Y.; Takeuchi, T.; Tamiya, E.; Karube, I.; Nishlyama, M.; Horinouchi, S.; Beppu, T.; Kadoi, H.; Uchiyama, S.;Suzuki, S.;Suzuki, M. .Electroanalysis 1992, 4, 771-776. Legall, J.; Moura, J. J. G. Eur. J. Moreno, C.; Franco, R.; Moura, I.; Biochem. 1993, 277, 981-989. Butt, J. N.; Sucheta, A.; Armstrong, F. A.; Breton, J.; Thomson, A. J.; Hatchikian, E. C. J. Am. Chem. Soc. 1993, 115, 1413-1421. (a) Song, S.; Clark, R. A,; Bowden, E. F.; Tarlov, M. J. J. Phys. Chem. 1993, 97, 6564-6572. (b) Bartlett, P. N.; Carwna, D. J. Analyst 1992, 117, 1287-1292. Collinson, M.; Bowden, E. F.; Tarlov, M. J. Langmulr 1992, 8, 12471250 _. .
Cooper, J. M.; Greenough, K. R.; McNell. C. J. J. Electroanal. Chem. 1993. 347. 267-275. Reeves, J. H.; Song, S.; Bowden, E. F. Anal. Chem. 1993, 65,683-688. Ueyama, S.; Wada, 0.;Mlyamoto, M.;Kawakubo, H.; Inatomi, K.; Isoda, S . J. Electroanal. Chem. 1993, 347, 443-449. Niwa, M.; Fukui, H.; Higashi, N. Macromolecules 1993,26,5816-5818. Hobara, D.; Niki, K.; Cotton, T. M. DenkiKagaku 1993. 67, 776-777. Coilinson, M.; Bowden, E. F. Anal. Chem. 1902. 64, 1470-1476. Schlereth, D. D.; Mantele, W. Biochem/stry 1903, 32, 1118-1 126. Schlereth, D. D.; Fernandez, V. M.; Manteie, W. Biochem/stry1993,32, 9199-9208. Tominaga, M.; Kumagai, T.; Takita, S.; Taniguchi, I. Chem. Lett. 1993, 1771-1774. Taniguchl, I.; Watanabe, K.; Tominaga, M.; Hawkridge, F. M. J. EleCtfoanal. Chem. 1992, 333, 331-338. King, B. C.; Hawkridge,F. M.; Hoffman, B. M. J. Am. Chem. SOC.1992, 714, 10603-10608.
Detrich, J. L.; Erb, G. A.; Beres, D. A.; Rlckard, L. H. I n Charge and FWEffects In Bbsystems-3; Allen, M. J., Cleary, S. F., Sowers, A. E., Shillady, D. D., Eds.; Birkhauser: Boston, 1992 pp 41-52. Ohno, H.; Tsukuda, T. J. Electroanal. Chem, 1992, 347, 137-149. Dong, S. J.; Chu, Q. H. Electroanalysk 1993, 5, 135-140. Zhou, J. X.; Wang, E. Electrochlm. Acta 1992, 37, 595-602. Cullison, J. K.; Hawkridge, F. M.; Nakashlma, N.; Hartzell, C. R. I n Charge and Field Effects In Blosystems-3; Alien, M. J., Clary, S. F., Sowers, A. E., Shillady, D. D., Eds.; Blrkhauser: Boston, 1992; pp
29-40.
Salamon, 2.; Hazzard, J. T.; Tollln, 0. Roc. Natl. Acad. Scl. U.S.A.
1993, 90, 6420-8423.
Sucheta, A.; Ackrell, 8. A. C.; Cochran, 8.; Armstrong, F. A. Nature
1992, 356, 361-382. .
. Sucheta. A.; Cammack, R.; Weiner, J.; Armstrong, F. A. Blochemlstty
1993, 32, 5455-5465. (G101) Kinnear, K. T.; Monbouquette, H. G. Langmulr 1993, 9, 2255-2257. (G102) Klnnear, K. T.; Monbouquette,H. 0. Blotechnol. Bloeng. 1993,42,1401A A
(G103) Bknco, P.; Haladjian, J. J. Electrochem. SOC.1992, 739, 2428-2432. Shlyk, M. A.; Krasnovskli, A. A. (0104) Nlkandrov, V. V.; Arlstarkhov, A. I.; Dokl. Akad. Nauk USSR 1991, 319, 151-154. (0105) Azab, H. A.; Bancl, L.; Borsarl, M.; Luchlnat, C.; Sola, M.; Viezzoli, M. S. Inorg. Chem. 1992, 37,4649-4655. (G106) Borsarl, M.; Azab, H. A. Bloelectrochem. Bhnerg. 1992,27,229-233. (G107) Shlnohara, H. Denki Kagaku 1993, 67, 780-782. (0108) Zhao, J. G.; Henkens, R. W.; Stonehuerner, J.; Waly, J. P.; Crumbllss, A. L. J. Electroanal. Chem. 1992, 327, 109-119. (G109) Ikeda, T.; Mlyaoka, S.; Matsushita, F.; Kobayashi, D.; Senda, M. Chem. Lett. 1992. 847-850. (G110) Fiores, J. R.; Ahrarez, J. M. F. Electroanalysls 1992, 4, 347-354. (G111) Leonhard, M.; Mantele, W. Biochemistry 1993, 32, 4532-4538. (G112) . . Bauscher, M.; Leonhard, M.; Moss, D. A.; Mantele, W. Blochlm. Blophys. . . Acta 1993, 7783, 59-71. (0113) Pauisen, K. E.; Orvllb, A. M.; Frerman, F. E.;Lipscomb, J. D.; Stankovlch, M. T. Bbchemlstty 1992, 37, 11755-11761. (0114) Durliat, H.; Courteix, A.; Bergel, A,; Comtat, M. J. Chlm. phys., Phys.Chlm. Blol. 1993, 90, 1113-1 135. (G115) Coury, L. A.; Liu, Y.; Murray, R. W. Anal. Chem. 1993, 65, 242-246. (Gll6) Sagara, T.; Kolde, T.; Saito, H.; Akutsu, H.; Niki, K. Bull. Chem. SOC. Jpn. 1992, 65, 424-429. (G117) Randrlamahazaka, H.; Nigretto, J. M. Anal. Chlm. Acta 1992, 257, 247-256. (G118) Randrlamahazaka,H. N.; Nlgretto, J. M. Electroanalysis 1993, 5. 231241. (0119) Roscoe, S. G.; Fuller, K. L.; Robitallle, G. J. Colloid Interface Scl. 1993, 760, 243-251. (G120) Relpa, V.; Gaigaias, A.; Abramowitz, S. J. Electroanal. Chem. 1993, 348, 413-428. (G121) Asanov, A. N.; Larina, L. L. I n ChargeandFle~EtfectsinBiosystems-3 Allen, M. J., Cleary, S. F., Sowers, A. E., ShiHady, D. D., Eds.; Birkhauser: Boston, 1992; pp 13-28. (G122) Katz, E. Y.; Solovev, A. A. Anal. Chlm. Acta 1992. 266, 97-106. (0123) Solovev, A. A.; Katz, E. Y.; Shuvalov, V. A.; Erokhln, Y. E. Sov. Electrochem. 1992, 28, 1448-1456. (G124) Cai, R.; Baba, R.; Hashimoto, K.; Kubota, Y.; Fujlshlma, A. J. Electroanal. Chem. 1993, 360, 237-245. (G125) Agostlano, A.; Goetze, D. C.; Carpentler, R. Electrochlm. Acta 1993, 38, 757-762. (G126) Janata, J. Anal. Chem.. review in this issue, (G127) Anderson, D. J.; Van Lente, F. Anal. Chem. 1993, 65, 364R-484R. (G128) Hecht, H. J.; Kalisz, H. M.; Hendle, J.; Schmld, R. D.; Schomburg, D. J. Mol. Blol. 1993, 229, 153-172. (G129) Reach, G.; Wilson, G. S. Anal. Chem. 1992, 64. 381A-386A. (G130) Albery, W. J.; Bartlett, P. N.; Drlscoll, B. J.; Lennox, R. B. J. Electroanal. Chem. 1992, 323, 77-102. (G131) Albery, W. J.; Kalia, Y. N.; Magner, E. J. Electroanal. Chem. 1992,325, 83-93. (G132) Sorochinskll, V. V.; Kurganov, B. I. Sov. Electrochem. 1992, 28, 153157. (GI331 Marcheslello, M.; Genies, E. J. Ektroanal. Chem. 1993, 358, 35-48. (G134) Tatsuma, T.; Watanabe, T. Anal. Chem. 1993. 65, 3129-3133. (G135) Bacha, S.; Bergel, A.; Comtat, M. J. Electroanal. Chem. 1993, 359, 21-38. (0136) Battagiinl, F.; Calvo, E. J. Anal. Chlm. Acta 1992, 258, 151-160. (G137) Randrlamahazaka, H.; Nigretto, J. M. Electroanalysis 1993, 5, 221230. (G138) Uhegbu, C. E.; Lim, K. B.; Pardue, H. L. Anal. Chem. 1993, 65, 24432451. (G139) Uhegbu, C. E.; Pardue, H. L.; Love, M. D.; Toosi, S. Anal. Chlm. Acta 1993, 287, 549-555. (G140) Lyons, M. E. G.; Lyons, C. H.; Mlchas, A,; Bartlett, P. N. Analyst 1992, 777, 1271-1280. ((3141) Tatsuma, T.; Watanabe, T.; Okawa, Y. Anel. Chem. 1992. 64, 830835. (G142) Tatsuma, T.; Watanabe, T. Anal. Chem. 1092, 64, 625-630. (G143) Badia, A.; Carllnl, R.; Fernandez, A,; Battaglinl, F.; Mlkkelsen, S. R.; Engllsh, A. M. J. Am. Chem. SOC. 1993, 715, 7053-7060. (G144) Bourdillon, C.; Demallle, C.; Moiroux, J.; Saveant, J. M. J. Am. Chem. SOC. 1993, 715, 2-10. (G145) Kajiya, Y.; Yoneyama, H. J. Electroanal. Chem. 1992, 328, 259-269. (0146) Kajlya, Y.; Yoneyama, H. J. Electroanal. Chem. 1992, 347, 85-92. (0147) Aokl. A.; Helier, A. J. Phys. Chem. 1993, 97, 11014-11019. (G148) Vreeke, M.; MaMan, R.; Heller, A. Anal. Chem. 1992, 64,3084-3090. (G149) Katakis. I.; Heller, A. Anal. Chem. 1992, 64, 1008-1013.
(G150) Ye, L.; Himmerle, M.; Olsthoorn, A. J. J.; Schuhmann. W.; Schmidt, H.-L.; Duine. J. A.; Heller, A. Anal. Chem. 1993, 65, 238-241. (0151) Ohara, T. J.; Vreeke, M. S.; Battagllni, F.; Heller. A. Electroanalysis 1993, 5. 825-831. (G152) Gargullo, M. G.; Huynh, N.; Proctor, A.; Mlchael. A. C. Anal. Chem. 1993, 65, 523-528. (G153) Dressman, S. F.; Gargullo, M. 0.;Sullenberger, E. F.; Michael, A. C. J. Am. 0".Soc. 1993, 175, 7541-7542. (G154) Iljima, S.; Mizutani, F.; Yabukl, S.; Tanaka. Y.; Asai, M.; Katsura. T.; Hosaka, S.; Ibonai, M. Anal. Chlm. Acta 1993, 287, 483-487. (G155) Hendry, S. P.; Cardosi, M. F.; Turner, A. P. F.; Neuse, E. W. Anal. Chim. Acta 1993, 287, 453-459. (G156) Hale, P. D.; Lee, H. S.; Okamoto, Y. Anal. Lett. 1993, 26, 1-16. (G157) Cahro, E. J.; Danilowlcz, C.; Dlaz, L. J. Chem. Soc., Faraday Trans. 1993, 89, 377-364. (G158) Chen. C. J.; Liu. C. C.; Savlnell, R. F. J. Electroanel. Chem. 1993, 348. 3 17-338. (G159) Lee, H. S.; Llu. L. F.; Hale, P. D.; Okamoto, Y. Hetemat. Chem. 1992. 3, 303-310. (G180) Arai, 0.; Masuda, M.; Yasumori, I. Chem. Lett. 1992, 1791-1794. (G161) BBlanger, D.; Nadreau, J.; Fortler, 0.Electroanalysk 1992,4,933-940. (G162) Cooper, J. M.; Bloor, D. Electroanalysk 1993, 5, 883-886. (Gl63) Caselli, M.; Dekmonica. M.; Portaccl, M. J. Electroanal. Chem. 1991, 319, 361-364. (G164) Tatsuma, T.; Gondaira, M.;Watanabe, T. Anal. Chem. 1992,64,11831187. (G165) Tatsuma, T.; Watanabe, T.; Watanabe, T. J. Electroanel. Chem. 1993, 356, 245-253. (0166) Bartlett, P. N.; Ali, 2.; Eastwickfield, V. J. Chem. Soc., Farady Trans. 1992, 88, 2677-2683. (G167) KaJlya, Y.; Matsumoto, H.; Yoneyama, H. J. Electroanal. Chem. 1991, 319. ., 185-194. .. (G168) Khan, G. F.; Kobatake, E.; Ikarlyama, Y.; Aizawa, M. Anal. Chlm. Acta 1993. 287. 527-533. (Gl69) Begum, A.; Kobatake, E.; Suzawa, T.; Ikarlyama, Y.; Alzawa, M. Anal. Chlm. Acta 1993, 280, 31-36. (G170) Sun, 2. S.; Tachikawa, H. Anal. Chem. 1992, 64. 1112-1117. (G171) Lyons, M. E. G.; Lyons, C. H.; Fitzgerald, C.; Bannon. T. Analyst1993, 778, 361-369. (G172) Cooper, J. C.; Hail, E. A. H. €lectroanalysk 1993, 5, 385-397. (G173) Haruyama, T.; Shlnohara, H.; Ikarlyama, Y.; Alzawa. M. J. Electroanal. Chem. 1993, 347, 293-301. (G174) Sadlk, 0. A.; Wallace, 0. 0. Anal. Chim. Acta 1993, 279, 209-212. (0175) Wolowacz, S. E.; Hin, B. F. Y. Y.; Lowe, C. R. Anal. Chem. 1992, 64, 1541- 1545. (0176) Yonhln. B. F. Y.; Smolander. M.; Crompton, T.; Lowe, C. R. Anal. Chem. 1993, 65, 2067-2071. (G177) Cosnler, S.; Innocent, C. J. Elechoanal. Chem. 1992, 328, 361-366. (G178) Cocheguerente, L.; Cosnier, S.; Innocent, C.; Maiiley, P.; Moutet, J. C.; Morelis,R. M.; Leca, B.; Coubt, P. R. Electroanalysls 1993,5,647-652. (G179) Wang, L.; Kobatake, E.; Ikariyama, Y.; Alzawa, M. DenklKagaku 1992, 60, 1050-1055. (G180) Koopel, C. G. J.; DeruRer, 8.; Nolte, R. J. M. J. Chem. Soc., Chem. Common. 1991, 1691-1692. (G181) Khan, 0. F.; Kobatake, E.; Shinohara, H.; Ikarlyama, Y.; Aizawa, M. Anal. Chem. 1992, 64, 1254-1258. (G182) Nlshlzawa, M.; Matsue, T.; Uchida, I. Anal. Chem. 1992, 64, 26422644. (G183) Hoa, D. T.; Kumar, T. N. S.; Punekar. N. S.; Srlnivasa, R. S.; Lal, R.; Contractor, A. Q. Anal. Chem. 1992, 64, 2645-2646. (G184) Bartlett, P. N.; Birkln, P. R. Anal. Chem. 1993, 65, 1118-1119. (G185) Maldan, R.; Heller, A. Anal. Chem. 1992, 64, 2889-2896. (G186) Christie, I. M.; Treioar, P. H.; Vadgama, P. Anal. Chlm. Acta 1992,269.
-- .-.
k6-79
(G187) Lowry, J. P.; O'Nelll, R. D. J. Electroanal. Chem. 1992, 334, 183-194. (G188) Centonze, D.; Guerrlerl. A,; Malltesta, C.; Palmlsano, F.; Zambonin, P. G. Fresenlus J. Anal. Chem. 1992, 342, 729-733. (G189) Lowry, J. P.; ONeIll, R. D. Anal. Chem. 1992, 64, 453-456. (G190) Palmisano, F.; Zambonln, P. G. Anal. Chem. 1993, 65, 2690-2692. (G191) Chrlstle, I. M.; Vadgama, P.; Lloyd. S. Anal. Chim. Acta 1993, 274, 191-199. (G192) Bartlett, P. N.; Tebbutt, P.; Tyrrell. C. H. Anal. Chem. 1992, 64, 138142. (G193) Mlzutanl, F.; Yabuki, S.; Katsura, T. Anal. Chlm. Acta 1993,274, 201207. (G194) Fortler, G.; Valllancourt, M.; Belanger, D. Electroanalysis 1992. 4, 275283. ((3195) Wang, J.; Lln, Y. H.; Chen, Q. Electroanalysis 1993, 5, 23-28. (G198) Wang, J.; Lin, Y. H.; Eremenko, A. V.; Ghlndllis. A. L.; Kurochkin, I. N. Anal. Lett. 1993, 26, 197-207. (G197) Scott, D. L.; Paddock, R. M.; Bowden, E. F. J. Electroanel. Chem. 1992, 347, 307-321. (G198) Armstrong, F. A.; Bond, A. M.; Buchl, F. N.; Hamnett, A.; HIII, H. A. 0.; Lannon, A. M.; Lettlngton, 0. C.; Zoskl, C. G. Analyst 1993, 778,973978. (GI99 Ho, W. 0.;Athey, D.; Mcneli, C. J.; Hager, H. J.; Evans, G. P.; Mullen, W. H. J. Electroanal. Chem. 1993, 351, 185-197. (G200) Kulys, J.; Bllitewski, U.; Schmid, R. D. Bbelectrochem. Bbenerg. 1991, 26, 277-288. (G201) Tatsuma, T.; Watanabe, T. Anal. Chem. 1992, 64, 143-147. (G202) Kobayashi, D.; Ozawa, S.; Mihara, T.; Ikeda. T. h n k l Kagaku 1992, 60, 1056-1062. (0203) Bourdillon, C.; Delamar, M.; Demallle. C.; Hltmi. R.; Molroux, J.; Pinson, J. J. Electroanel. Chem. 1992. 336. 113-123. (G204) Wlllner, I.; Katz, E.; Rlklln, A.; Kasher, R. J. Am. Chem. Soc. 1992, 714, 10965-10966.
Analytical Chemistty, Vol. 66, No. 12, June 15, 1994
423R
(G205) Katz, E.; Riklin, A.; Willner, I. J. Electroanal. Chem. 1993, 354, 129144. (G206) SneJdarkova, M.; Rehak. M.; Otto, M. Anal. Chem. 1993,65.665-668. (G207) Lee, Y. W.; Reed-Mundell, J.; Sukenlk, C. N.; Zull, J. E. Langmulr 1993, 9, 3009-3014. (G208) Amador, S.M.; Pachence, J. M.; Flschetti, R.; McCauiey, J. P.; Smith, A. B., 111; Blasle, J. K. Langmulr 1993, 9, 812-817. (G209) Hong, H.-G.; Bohn, P. W.; Sligar, S.G. Anal. Chem. 1993, 65, 16351638. R.; Kumar. A.; WhitesMes, G. M. (G210) Lbpez, G. P.; Biebuyck. H. A.; -rliter, J. Am. Chem. Soc. 1993, 775, 10774-10781. (G211) Parpaleix, T.; Laval, J. M.; Majda, M.; Bourdillon, C. Anal. Chem. 1992, 64, 641-646. (G212) Dicks, J. M.; Cardosi, M. F.; Turner, A. P. F.; Karube, I.Electroanalysis 1993, 5, 1-9. (G213) Wollenberger, U.; Wang, J.; Ozsoz, M.; Gonzalez-Romero, E.; Scheller, F. Bioelectrochem. Bioenerg. 1991, 26, 287-296. (G214) Wang, J.; Gonzalezromero,E.; Ozsoz, M. Electroanalysis 1992,4539544. (G215) Wang, J.; Romero, E. 0.; Revielo, A. J. J. Electroanal. Chem. 1993, 353, 113-120. (G216) Wang, J.; Revbjo, A. J.; Angnes, L. Electroanalysis 1993, 5, 575-579. (G217) Mlzutani, F.; Yabuki, S.; Katsura, T. Denkl Kagaku 1992, 60, 11411142. (G218) Kulys, J.; Wang, L. 2 . ; Daugvilaiite, N. Anal. Chim. Acta 1992, 265, 15-20. (G219) Kulys, J.; Wang, L. 2.; Maksimovlene, A. Anal. Chim. Acta 1993, 274, 53-58. .. .. (G220) Kuiys, J.; Glelxner, G.; Schuhmann, W.; Schmldt, H. L. Electroanalysis 1993. 5. 201-207. (G221) Kulys; J.; Wang, L. 2 . ;Razumas, V. Electroanalysis 1992, 4, 527-532. (G222) Smlt, M. H.; Rechnitz, G. A. Electroanalysis 1993, 5, 747-751. (G223) Amine, A.; Kauffmann, J. M.; Guilbauit, G. G.; Bacha, S.Anal. Lett. 1993, 26, 1281-1299. (G224) Rosenmargalit, 1.; Bettelhelm, A.; Rishpon, J. Anal. Chlm. Acta 1993, 287, 327-333. (G225) Pantano, P.; Kuhr, W. G. Anal. Chem. 1993, 65, 623-630. (G226) Csoregi, E.; Gorton, L.; Markovarga, G. Anal. Chlm. Acta 1993, 273, 59-70. (G227) Pariente, F.; Hernandez, L.; Abruna, H. D.; Lorenzo, E. Anal. Chim. Acta 1993, 273, 187-193. (G228) Wang, D. L.; Heller, A. Anal. Chem. 1993, 65, 1069-1073. (G229) Kawagoe, J. L.; Nlehaus, D. E.; Wightman, R. M. Anal. Chem. 1991, 63, 2961-2965. (G230) Wang, J.; Angnes, L. Anal. Chem. 1992, 64, 456-459. (G231) Wang, J.; Naser, N.; Renschler, C. L. Anal. Lett. 1993, 26, 1333-1346. (G232) Yokoyama, K.; Nakajima, K.; Uchyama, S.;Suzuki, S.;Suzuki, M.; Takeuchi, T.; Tamiya, E.; Karube, I. Electroanalysls 1992, 4,859-864. (G233) Abe, T.; Lau, Y. Y.; Ewing, A. G. Anal. Chem. 1992, 64, 2160-2163. (G234) Motonaka, J.; Faulkner, L. R. Anal. Chem. 1993, 65, 3258-3261. (G235) Bartlett, P. N.; Caruana, D. J. Analyst 1992, 777, 1287-1292. (G236) Zhang, Y.; Wilson, G. S. J. Electroanal. Chem. 1993, 345, 253-271. (G237) Zhao, S.; Korell, U.; Cuccia, L.;Lennox, R. B. J. Phys. Chem. 1992, 96, 5641-5652. (G236) Wllde, C. P.; Hu, A.; Rondeau, C. M.; Wood, M. J. Electroanal. Chem. 1993, 353, 19-31. (G239) Korell, U.; Spichiger, U. E. Electroanalysis 1993, 5, 869-876. (G240) Sim, K. W. Anal. Chim. Acta 1993, 273, 165-174. (G241) Fraser, D. M.; Zakeeruddin, S. M.; Gratzel, M. J. Electroanal. Chem. 1993, 359, 125-139. (G242) Furbee, J. W.; Thomas, C. R.; Kelly, R. S.;Malachowski, M. R. Anal. Chem. 1993, 65, 1654-1657. (G243) Atanasov, P.; Kalsheva, A.; Gamburzev, S.; Iliev, I.; Bobrin, S. Electroanalysis 1993. 5, 91-97. (G244) Zhao, S. S.; Luong, J. H. T. Anal. Chim. Acta 1993, 282, 319-327. (G245) Kulys, J.; Buchrasmussen, T.; Bechgaard, K.; Marclnkeviciene, J.; Hansen. H. E. Anal. Lett. 1993, 26, 2535-2542. (G246) Ikeda, T.; Kurosaki, T.; Takayama, K.; Kinoshita, H. Denki Kagaku 1993, 67, 889-890. (G247) Takayama, K.; Kurosaki, T.; Ikeda. T. J. Electranal. Chem. 1993, 356, 295-301 -- - - - . . (G248) Cohen, C. B.; Weber, S. G. Anal. Chem. 1993, 65, 169-175. (G249) Ballarin, B.; Brumlik, C. J.; Lawson, D. R.; Liang, W. B.; Vandyke, L. S.; Martin, C. R . Anal. Chem. 1992, 64, 2647-2651. (G250) Nikolelis,D. P.; Tzanelis, M. G.; Kruil, U. J. Anal. Chim. Acta 1993, 287, 569-576. (G251) Audebert, P.; Demallle, C.; Sanchez, C. Chem. Mater. 1993, 5, 911913. (G252) Ellerby, L. M.; Nishlda, C. R.; Nishida, F.; Yamanaka, S.A.; Dunn, B.; Valentine, J. S.;Zink, J. 1. Science 1992, 255, 1113-1115. (G253) Palecek, E.; Jelen, F.; Teijeiro, C.; Fucik. V.; Jovin, T. M. Anal. Chim. Acta 1993, 273, 175-186. (G254) Teijeiro, C.; Nejedly, K.; Palecek, E. J. Blomol. Struct. Dynam. 1993, 77, 313-331. (G255) Maeda, M.; Mitsuhashi, Y.; Nakano, K.; Takagl, M. Anal. Scl. 1992, 8,
__
83-84.
(G256) Millan. K. M.; Spurmanis, A. J.; Mlkkeisen, S.R. Electroanalys/s 1992, 4. 929-932. (0257) Rodriguez, M.; Bard, A. J. Inwg. Chem. 1992, 37, 1129-1135. (G258) Grover, N.; Gupta, N.; Singh, P.; Thorp, H. H. Inorg. Chem. 1992, 37, 20 14-2020. (G259) Gupta, N.; Grover, N.; Neyhart, G. A.; Llang. W.; Slngh, P.; Thorp, H. H. Angew. Chem., Int. Ed. Engl. 1992, 37, 1046-1050. (G260) Ohasemzadeh, M. B.; Capella, P.; Mhcheil, K.; Adams, R. N. J. Neurochem. 1993, 60, 442-448.
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AnalyticalChemistry, Vol. 66,No. 12, June 15, 1994
(G261) Capella, P.; Ohasemzadeh, M. B.; Adams, R. N.; Wiedemann, D. J.; Wightman, R . M. J. N e m h e m . 1993, 60, 449-453. (G262) Young, S.D.; Michael, A. C. Brain Res. 1993, 600, 305-307. (G263) Oneill, R. D. Analyst 1993, 778, 433-438. (G264) Wledemann, D. J.; Kawagoe, K. T.; Kennedy, R. T.; Ciolkowskl, E. L.; Wightman, R. M. Anal. Chem. 1991, 63, 2965-2970. (G265) A m , W. J.; Boutelk M.G.; Gaky, P. T. J. Chem.Soc., Chem.Commun. 1992, 900-901. (G266) Hu, Y. 8.; Zhang, Y. N.; Wilson, G. S. Anal. Chlm. Acta 1993, 287, 503-5 11. (G267) Zhang, Y.; Wilson, G. S. Anal. Chlm. Acta 1993, 287, 513-520. (G268) Lau, Y. Y.; Abe, T.; Ewing, A. G. Anal. Chem. 1992, 64, 1702-1705. (G269) Lau, Y. Y.; Wong, D. K. Y . ; Ewlng, A. G. Mlcrochem. J. 1993, 47, 308-316. (G270) Chen, T. K.; Lau, Y. Y.; Wong, D. K. Y . ; Ewing, A. G. Anal. Chem. 1992, 64, 1264-1268. (G271) Schroeder, T. J.; Jankowski, J. A.; Kawagoe, K. T.; Wightman, R. M.; Lefrou, C.; Amatore, C. Anal. Chem. 1992, 64, 3077-3063. (G272) Kennedy, R. T.; Huang, L.; Atkinson, M. A.; Dush, P. Anal. Chem. 1993, 65, 1882-1887. (G273) Limoges, B.; Degrand. C.; Brossier, P.; Blankespoor, R. L. Anal. Chem. 1993, 65, 1054-1060. (G274) Lasalle, A. L.; Limoges. 8.; Anizon, J. Y.; Degrand, C.; Brossier, P. J. Electroanal. Chem. 1993, 350, 329-335. (G275) Yamaguchi, S.;Ozawa, S.; Ikeda, T.; Senda, M. Anal. Scl. 1992, 8, 87-88. (G276) Thompson, R. Q.; Porter, M.; Stuver, C.; Halsail, H. B.; Heineman, W. R.; Buckiey, E.; Smyth, M. R. Anal. Chim. Acta 1993, 277, 223-229. (0277) Huet. D.; Bourdiilon, C. Anal. Chim. Acta 1993, 272, 205-212. (G278) Minami, H.; Sugawara. M.; Odashima, K.; Umezawa, Y.; Uto, M.; Michaelis, E. K.; Kuwana, T. Anal. Chem. 1991, 63,2787-2795. (G279) Odashima, K.; Kotato, M.; Sugawara, M.; Umezawa, Y. Anal. Chem. 1993, 65, 927-936. (G280) Nikoielis, D. P.; Tzanelis, M. G.; Krull, U. J. Anal. Chlm. Acta 1993, 282, 527-534. (G281) Wang, J.; Lin, Y. H.; Eremenko, A. V.; Kurochkin, I. N.; Mlneyeva, M. F. Anal. Chem. 1993, 65, 513-516. (G282) Pierce, D. T.; Unwin, P. R.; Bard, A. J. Anal. Chem. 1992, 64, 17951804. (G283) Nhrens, D. E.; Chambers, J. Q.; Anderson, T. R.; White, D. C. Anal. Chem. 1993, 65, 65-69. (G284) Plant, A. L. Langmuir 1993, 9, 2764-2767.
H. CHARACTERIZATION OF REDOX REACTIONS (Hl) (H2) (H3) (H4) (H5) (He) (H7) (HE) (H9) WO) (H1V (H12) (H13) (H14) (H15) (H16) (H17) (H18) (H19) (H20) (H21) (H22) (H23) (H24) (H25) (H26) (H27) (H28)
Bond, A. M.; Coiton, R.; Hutton, R. S. Inorg. Chim. Acta 1992, 200, 671-677. Plerce, D. T.; Gelger, W. E. J. Am. Chem. Soc. 1992, 7 74,6063-6073. Huang, Q. D.; Gosser, D. K. Tabnta 1992, 39, 1155-1161. Andrieux, C. P.; Delgado, G.; Saveant, J. M. J. Electroanal. Chem. 1993, 348. 123-139. Andiieux, C. P.; Differdlng, E.; Robert, M.; Saveant, J. M. J. Am. Chem. Soc. 1993. 775. 6592-6599. Yang, H. J'.; Bard, A. J. J. Electroanal. Chem. 1992, 339, 423-449. Yang, H. J; Wlpf, D. 0.; Bard, A. J. J. Electroanal. Chem. 1992, 337, 913-924. Andrieux, C. P.; Haplot, P.; Pinson, J.; Saveant, J. M. J. Am. Chem. Soc. 1993, 7 75, 7783-7788. Bond, A. M.; Feldberg, S.W.; Greenhill, H. B.; Mahon, P. J.; Coiton, R.; Whyte, T. Anal. Chem. 1992, 64, 1014-1021. Lemos, M. A. N. D. A.; Pombeiro, A. J. L. J. Organomet. Chem. 1992, 438, 159-165. Anxolabehere, E.; Lexa, D.; Saveant, J. M. J. phys. Chem. 1992, 96, 1266-.. 1270. - . Brielbeck, B.; Ruhi, J. C.; Evans, D. H. J. Am. Chem. Soc. 1993, 775, 11898- 11905. Nelsen, S.F.; Chen, L. J.; Petlllo. P. A.; Evans, D. H.; Neugebauer, F. A. J. Am. Chem. Soc. 1993, 775, 10611-10620. Marioli, J. M.; Kuwana, T. Electrochim. Acta 1992, 37, 1167-1197. Burke, L. D.; Ryan, T. G. Electrochlm. Acta 1992, 37, 1363-1370. Kadirgan, F. Electrochim. Acta 1992, 37, 2651-2657. Becerik, I.; Parpot, P.; Kokoh, K. B.; Beden, B.; Lamy, C. Electrochim. Acta 1993, 38, 1679-1683. Kokoh, K. B.; Leger, J. M.; Beden, B.; Lamy, C. Electrochlm. Acta 1992, 37, 1333-1342. Kokoh, K. 8.; Parpot, P.; Belgsir, E. M.; Leger, J. M.; Beden, B.; Lamy. C. Electrochlm. Acta 1993, 38, 1359-1365. Ruhl, J. C.; Evans, D. H.; Neta, P. J. Electroanal. Chem. 1992, 340, 257-272. Lavlron, E.; Meunier-Prest, R.; Vallat, A.; Roulliir, L.; Lacasse, R. J. Electroanal. Chem. 1992, 347, 227-255. Danclu, V.; Martre, A. M.; Pouillen, P.; Mousset, G. Electrochim. Acta 1992. 37. 1993-2000. Danciu, V.;Martre, A. M.; Pouillen, P.; Mousset, G. Electrochim. Acta 1992, 37, 2001-2008. Baumane, L.; Stradins, J.; Gavars, R.; Duburs, G. Electrochim. Acta 1992, 37, 2599-2610. Dumanovlc, D.; Jovanovlc, J.; Suznjevlc, D.; Erceg, M.; Zuman, P. Electroanalysls 1992, 4, 795-800. Miraliesroch, F.; Tallec, A.; Tardhrel, R. Electrochim. Acta 1993, 38, 963-968. Anne, A.; Hapiot, P.; Moiroux, J.; Neta, P.; Saveant, J. M. J. Am. Chem. SOC. 1992, 774, 4694-4701. Anne, A.; Haplot, P.; Molroux, J.; Saveant, J. M. J. Electroanal. Chem. 1992, 337,959-970.
Medebieiie, M.; Pinson, J.; Saveant, J. M. Tetrahedron Le#. 1002,33, 7351-7354. Combellas, C.; Marzouk, H.; Suba, C.; Thiebault, A. Synthesis 1003, 788-790. Mortensen, J.; Heinze, J.; Herbst, H.; Muiien, K. J. Elecfroanal. Chem. 1092,324,201-217. Cieghorn, S. J. C.; Pietcher, D. Elecfrochim. Acta 1093. 38, 425-430. Cleghorn, S. J. C.; Pletcher, D. Electrochim. Acfa 1003, 38, 26832689. k h d a v i , B.; Chapuzet, J. M.; Lessard, J. Electrochim. Acta 1003,38, 1377-1380. Momota, K.; Morlta, M.; Matsuda, Y. Electrochim. Acta 1003,38,619624. Deigado, M.; Wolf, R. E.; Hartman, J. R.; McCafferty, 0.; Yagbasan, R.; Rawie, S. C.; Watkin, D. J.; Cooper, S. R. J. Am. Chem. SOC. 1002, 774, 8983-8991. Urove. G. A.; Peters, D. G. J. Electrochem. SOC.1003, 740, 932-935. Pritts, W. A.; Vielra, K. L.; Peters, D. G. Anal. Chem. 1003,65, 21452149. Wandlowski, T.; Gosser, D.; Akinele, E.; DeLevie, R.; Horak, V. Taknta 1003,40,1789-1798. Geiger, W. E.; Rieger, P. H.; Corbato, C.: Edwin, J.; Fonseca, E.; Lane, G. A.; Mevs, J. M. J. Am. Chem. Soc. 1003, 775,2314-2323. Oseila, D.; Fiedier, J. Organometallics 1002. 77. 3875-3878. Oseila, D.; Posplsil, L.; Fiedier, J. Organometallics 1003, 72, 31403144. Karpinski, 2. J.; Kochi, J. K. Inorg. Chem. 1002,37,2762-2767. Sanauiiah; Kano, K.; Glass, R. S.; Wilson, G. S. J. Am. Chem. SOC. 1903, 775,592-600. Savaranamuthu, A.; Bruce, A. E.; Bruce, M. R. M.; Fermin, M. C.; Hneihen, A. S.; Bruno, J. W. Organomfallics 1092, Boudon, C.; Gisselbrecht,J. P.; Gross, M.; Benabdailah, T.; Gugiieimetti, R. J. Elechoanal. Chem. 1003,345, 363-376. McDevltt, M. R.; Addison, A. W. Inorg. Chim. Acta 1003,204,141-146. Desantis, G.; Fabbrizzi, L.; Licchelli, M.; Mangano, C.; Pallavicini, P.; Poggl, A. Inorg. Chem. 1003,32, 854-860. Mu, X. H.; Schultr, F. A. Inorg. Chem. 1002,37. 3351-3357. Chiistunoff, J. B.; Bard, A. J. Inorg. Chem. 1992,37,4582-4587. Chiistunoff, J. B.; Bard, A. J. Inorg. Chem. 1093,32, 3521-3527. Bard, A. J.; Garcia, E.; Kukharenko, S.; Strelets, V. V. Inorg. Chem. 1903,32, 3528-3531. Adeyemi, S. A.; Dovietogiou, A.; Guadaiupe, A. R.; Meyer, T. J. Inorg. Chem. 1002,37, 1375-1383. Roffia, S.; Marcaccio, M.; Paradisi. C.; Paolucci, F.; Balzani, V.; Denti, G.; Serroni, S.; Campagna, S. Inorg. Chem. 1903,32, 3003-3009. Krejcik, M.; Vicek, A. A. Inorg. Chem. 1092,37,2390-2395. Deblas, A.; Desantis, G.; Fabbrlzzi, L.; Liccheili, M.; Lanfredi, A. M. M.; Paiiavicinl, P.; Poggi, A.; Ugozzoii, F. Inorg. Chem. 1903,32, 106-1 13. Kadish, K. M.; van Caemeibecke, E.; Boulas, P.; Dsouza, F.; Vogei, E.; Kisters, M.; Medforth, C. J.; Smith, K. M. Inorg. Chem. 1003,32,41774178. GuMi. D. M.; Hambright, P.; Lexa, D.; Neta, P.; Saveant, J. M. J. Phys. Chem. 1902,96, 4459-4466. Kadish, K. M.; Hu, Y.; Boschl, T.; Tagliatesta, P. Inorg. Chem. 1093, 32,2996-3002. Kadish. K. M.; Dsouza, F.;van Caemelbecke, E.; Viilard, A.; Lee, J. D.; Tabard, A.; Guilard, R. Inorg. Chem. 1093,32, 4179-4185. StoJanovic, R. S.; Bond, A. M. Anal. Chem. 1993,65,56-64. Mandier, D. J. Nectrochem. Soc.1003, 740, Kamlnsky, A.; Wiliner, I.; L25-L27. Xie, Q.S.; Perezcordero, E.; Echegoyen, L. J. Am. Chem. SOC.1902, 7 74, 3978-3980. Zhou, F. M.; Jehouiet, C.; Bard, A. J. J. Am. Chem. SOC. 1002, 774, 11004-11006. Fawcett, W. R.; Opaiio, M.; Fedurco, M.; Lee, J. W. J. Am. Chem. SOC. 1003, 175, 196-200. Krishnan, V.; Moninot, G.; Dubois, D.; Kutner, W.; Kadish, K. M. J. Electroanal. Chem. 1903,356,93-107. Mkkln, M. V.; Bulhoes, L. 0. S.; Bard, A. J. J. Am. Chem. Soc. 1003, 775, 201-204. Xie, Q. S.; Arias, F.; Echegoyen, L. J. Am. Chem. SOC. 1003, 175, 98 18-981 9. Guarr, T. F.; Meier, M. S.; Vance, V. K.; Clayton, M. J. Am. Chem. SOC. 1003, 7 75,9862-9863. Penicaud, A.; Perezbenitez, A.; Gieason, R.; Munoz, E.; Escudero, R. J. Am. Chem. SOC.1093, 775, 10392-10393. Wudl, F.; Thiigen, C.; Whetten, R. L.; Diederich, F. J. Am. Chem. Li, Q.; SOC. lS02, 774, 3994-3996. Lerke, S. A.; Parkinson, E. A.; Evans, D. H.; Fagan, P. J. J. Am. Chem. SOC. 1002, 114, 7807-7813. Koefod, R. S.;Xu, C. J.; Lu, W. Y.; Shapiey, J. R.; Hili. M. G.; Mann, K. R. J. Phys. Chem. 1002,96, 2928-2930. Sudha, C.; Mandai, S. K.; Chakravarty, A. R. Inorg. Chem. 1903,32, 380 1-3802. Shibahara, T.; Yamasaki, M.; Sakane, 0.; Mlnami, K.; Yabuki, T.; Ichimura, A. Inorg. Chem. 1002,37,640-647. Coe, B. J.; Jones, C. J.; McCleverty, J. A,; Bruce, D. W. Inorg. Chlm. Acta 1903,206, 41-46. Holder, G. N.; Bottomiey, L. A. Inorg. Chim. Acta 1002, 794, 133-137. Heath, G. A.; Raptis, R. G. J. Am. Chem, SOC.1903, 175, 3768-3769. Oseiia, D.; Hanziik, J. Inorg. Chim. Acta 1003,213, 31 1-317. Cyr, J. E.; Linder, K. E.; Nowotnik, D. P. Inorg. Chim. Acfa 1093,206, 97-104. Choi, Y. K.; Kim, E. S.; Park, S. M. J. Electrochem. Soc. 1003, 140, 11-18. Opekar, F.; Langmaier, J. Talanta 1092, 39, 367-369.
(H83) Komeda. N.; Nagao, H.; Matsui, T.; Adachi. 0.; Tanaka, K.J. Am. Chem. SOC. 1992, 774, 3625-3630. (H84) Ratliff, K. S.; Lentz, R. E.; Kublak, C. P. Organomefallics 1002, 77, 1986-1 988. (Has) Arana, C.; Yan, S.; Keshavarzk, M.; POtts, K. T.; Abruna, H. D. Inwg. Chem. 1002,37,3680-3682. (H86) Bruce. M. R. M.; Megehee, E.; Sullivan, B. P.; Thorp, H. H.; O’Tooie. T. 4864-4873. R.; Downard. A.; Pugh, J. R.; Meyer, T. J. Inorg. Chem. 1002,37, YoshMa, T.; Tsutsumtda. K.; Teratani, S.; Yasufuku, K.; Kaneko, M. J. Chem. Soc., Chem. Commun. 1003,631-633. Bandi, A.; Kuhne, H. M. J. Elecfrochem. SOC.1002, 739, 1605-1610. Kyrlacou, G.; Anagnostopoulos, A. J. Elecboanal. Chem. 1002. 328, 233-243. Schwartz, M.; Cook, R. L.; Kehoe, V. M.; Macduff, R. C.; Patei, J.; Sammells, A. F. J. Electrochem. Soc. 1093, 740, 614-618. Ohkawa, K.; Hashlmoto, K.; Fujishima, A.; Noguchi, Y.; Nakayama, S. J. Elecfroanal. Chem. 1003,345,445-456. Ohkawa, K.; Noguchi. Y.; Nakayama, S.; Hashimoto, K.; Fujishima. A. J. Elecfroanal. Chem. 1003,346, 459-464. Kudo, A.; Nakagawa, S.; Tsuneto, A.; Sakata, T. J. Electrochem. SOC. 1903, 740, 1541-1545. Nagaoka, T.; Nishii, N.; Fujii, K.; Ogura, K. J. Electroanal. Chem. 1002, 322,383-389. Derien, S.; Ciinet, J. C.; Dunach, E.; Perichon, J. J. Organomefal. Chem. 1002,424. 213-224. Derien, S.; Clinet, J. C.; Dunach, E.;Perichon, J. J. Org. Chem. 1093, 58, 2578-2588. (H97) Derien, S.; Ciinet, J. C.; Dunach, E.; Perichon, J. Tetrahedron 1902,48, 5235-5248. (H98) Murcla, N. S.; Peters, D. G. J. Etectroanal. Chem. 1992,326, 69-79. (H99) Ogura, K.; Mine, K.; Yano, J.; Sugihara, H. J. Chem. Soc., Chem. Commun. 1093,20-21. (H100) Kyrlacou, G. 2.; Anagnostopoulos, A. K. J. Appl. Electrochem. 1003, 23,483-486. (HlOl) Naitoh, A.; Ohta, K.; Mizuno, T.; Yoshde, H.; Sakai, M.; Node, H. Electrochim. Acfa 1003,38, 2177-2179. (H102) Yahikozawa, K.; Nishimura, K.; Kumazawa. M.; Tateishi, N.; Takasu, Y.; Yasuda. K.; Matsuda, Y. Electrochim. Acta 1002, 37, 453-455. (H103) Aramata. A.; Toyoshima, I.; Enyo, M. Electrochim. Acta 1092, 37, 1317-1320. (H104) Bronoei, G.; Besse, S.; Tassin, N. Electrochlm. Acfa 1002,37. 13511353. (H105) Lai, Y. K.; Wong, K. Y. Electrochim. Acta 1903. 38, 1015-1021. (H106) Wong, K. Y.; Yam, V. W.; Lee, W. W. Nectrochim. Acta 1002,37. 2645-2650. (H107) Cavalca, C. A.; Larsen, G.; Vayenas, C. 0.; Hailer, G. L. J. phys. Chem. 1003,97, 6115-6119. (H108) Gasteiger, H. A.; Markovlc, N.; Ross, P. N.; Cairns, E. J. J. Phys. Chem. 1093. 97. 12020-12029. (H109) Karaman, R.; Jeon, S. W.; Aimarsson, 0.; Bruice, T. C. J. Am. Chem. SOC.1902, 7 74, 4899-4905. (H110) Hofseth, C. S.; Chapman, T. W. J. Electrochem. SOC.1002,739,25252529. (H111) Farmer, J. C.; Wang, F. T.; Lewis, P. R.; Summers, L. J. J. Electrochem. SOC. 1002, 739, 3025-3029. (H112) Lahiri, G. K.; Schussel, L. J.: Stoizenbera, A. M. Inora. Chem. 1002. 37,4991-5000. (Hl13) Lojou, E.; Devaud, M.; Heintz, M.; Troupel, M.; Perichon, J. Electrochim. Acta 1903,38, 613-617. (H114) Che, G. L.; Dong, S. J. Electrochim. Acfa 1903. 36, 1345-1349. (H115) Ma, L.; Li, H. L.; Cai, C. L. Electrochim. Acfa 1003,38, 2773-2775. (H116) Gur. T. M.; Huggins, R. A. J. Electrochem. Soc.1002, 739, L95-L97. (H117) Matsumoto, Y.; Sasaki, T.; Hombo, J. Inorg. Chem. 1002,37,738741. (H118) Wade, T.; Park, J. M.; Garza, E. G.; Ross, C. B.; Smith, D. M.; Crooks, R. M. J. Am. Chem. Sm. 1002, 774, 9457-9464. (H119) Singh, K.; Tanveer, R. J. Meter. Sci. Left 1003, 72, 737-738. (H120) Slngh. K.; Tanveer. M. R. J. Meter, Chem 1003,3, 1295-1298. (H121) Singh, K.; Shukla, A. K. Sol. Energ. Mater. Sol. Cells 1003,30. 169175 (H122) Dennison, S. Electrochim, Acfa 1003,38, 2395-2403. (H123) Roberts, G. L.; Kauziarich, S. M.; Glass, R. S.; Estili, J. C. Chem. Mater. 1093. 5. 1645-1650. (H124) Chakravorti, M. C.; Subrahmanyam, G. V. B. Po/yhedron 1002, 77, 3 19 1-31 95. (H125) Warren, C. J.; Ho, D. M.;Bocarsly, A. B.; Haushalter, R. C. J. Am. Chem. Soc.1993, 175. 6416-6417. (H126) Niyazymbetov. M. E.; Evans, D. H. J. Org. Chem. 1093.58,779-783. (H127) Niyazymbetov, M. E.;Evans, D. H. Tetrahedron 1093,49,9627-9688. (H128) Jutand, A.; Negri, S.; Mosieh, A. J. Chem. Soc., Chem. Commun. 1092. 1729-1730. (H129) Heintz. M.; Devaud, M.; Hebri, H.; Dunach, E.; Troupei, M. Tefrahedron 1003,49, 2249-2252. (H130) Gard. J. C.; Lessard, J.; Mugnier, Y. Nectrochim.Acta 1993,38,677680. (H131) Momota, K.; Morita. M.; Matsuda, Y. Electrochim.Acta 1093,36,11231130. (H132) Wendt, H.; Bitterllch, S. Electrochim. Acta 1092. 37, 1951-1958. (H133) Wendt, H.; Bitterlich, S.; Lodowicks, E.; Liu, 2. Electrochlm. Acfa 1092, 37, 1959-1969. (H134) Hughes, D. L.; Ibrahim, S. K.; Macdonald, C. J.; Ail, H. M.; Pickett, C. J. J. Chem. Soc., Chem. Common. 1902, 1762-1763. (H135) Markovic, N.; Ross, P. N. J. Phys. Chem. 1093,97, 9771-9778. (H136) Casanova, E. A.; Dutton. M. C.; Kalota, D. J.; Wagenknecht, J. H. J. Electrochem. Soc. 1003, 740, 2565-2567.
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(H137) Franklin, T. C.; Oliver, G.; Nnodimele, R.; Couch, K. J. Electrochem. SOC.1992, 739, 2192-2195. (H138) Kunai, A.; Toyoda, E.; Kawakami, T.; Ishikawa, M. Organometallics 1992, 7 7, 2899-2903. (H139) Chakravwti, M. C.; Ganguly, S.; Subrahmanyam, G. V. B.; Bhattacharb. M. Po/yhedron 1993, 72, 683-687. (HMO) Caron, C.; Subramanian, R.; Dsouza, F.; Kim, J.; Kutner, W.; Jones, M. T.: Kadish, K. M. J. Am. Chem. SOC. 1993, 775,8505-8506. (H141) Bouzek, K.; Rousar, I.Electrochim. Acta 1993, 38, 1717-1720. (H142) Nikitas, P. J. Electroanal. Chem. 1993, 348, 59-80. (H143) Myers, S. A.; Mackay, R. A.; Brajter-Toth, A. Anal. Chem. 1993, 65, 3447-3453. (H144) Abbott, A. P.; Gounili, G.; Bobbin, J. M.; Rusling, J. F.; Kumosinski, T. F. J. Phys. Chem. 1992, 96, 11091-11095. (H145) Abbott, A. P.; Miaw, C. L.; Rusling, J. F. J. Nectroanai. Chem. 1992, 327, 31-46. (H146) Gounili, G.; Miaw, C. L.; Bobblt, J. M.; Rusling, J. F. J. ColioidInterface Sci. 1992, 753, 446-456. (H147) Kamau, G. N.; Hu, N. F.; Rusling, J. F. Langmuir 1992, 8, 1042-1044. (H148) Iwunze, M. 0.;Hu. N. F.; Rusling, J. F. J. Electroanal. Chem. 1992, 333, 353-36 1. (H149) Sucheta, A.; Haque, I.U.; Rusling, J. F. Langmuir 1992, 8, 1633-1636. (H150) Takisawa, N.; Thomason, M.; Bloor, D. M.; Wynjones, E. J. Colloid Interface Sci. 1993, 757, 77-81. (H151) Phani, K.L.N.; Pitchumani,S.;Ravichandran,S.;Sekan, S.T.;Bharathey, S. J. Chem. Soc., Chem. Commun. 1993, 179-181.
I.SPECTROELECTROCHEMISTRY Pastor, E.; Schmidt, V. M.; Iwasita, T.; Arevalo, M. C.; Gonzaiez, S.; Arvia, A. J. Nectrochim. Acta 1993, 38, 1337-1344. Pastor, E.: Wasmus, S.;IwasZa,T.; Arevalo, M. C.; Gonzalez, S.; ANia, A. J. J. Electroanal. Chem. 1993, 353, 81-100. Pastor, E.; Wasmus, S.; Iwaslta, T.; Arevalo, M. C.; Gonzalez, S.; Arvia, A. J. J. Nectroanal. Chem. 1993, 350, 97-116. Wasmus, S.;Vielstlch, W. J. Appi. Electrochem. 1993, 23, 120-124. Munk, J.; Skou, E. SolM State Ionics 1992, 53-56, 875-881. Schmlemann, U.; Baltruschat, H. J. Electroanai. Chem. 1993, 347, 93-109. Wasmus, S.;Vielstich, W. J. Electroanal. Chem. 1993, 359, 175-191. Anastasijevic, N. A.; Baltruschat, H.; Heitbaum, J. Electrochim. Acta 1993, 38, 1067-1072. Wasmus, S.;Vielstich, W. Nectrochim. Acta 1993, 38, 185-189. Jusys, 2.; Vaskelis, A. J. Electroanal. Chem. 1992, 335, 93-104. Wasmus, S.;Vielstich, W. J. Nectroanal. Chem. 1993, 345, 323-335. Wasmus, S.; Vielstich, W. Nectrochim. Acta 1993, 38, 175-183. Cattaneo, E.; Rasch, B.; Vielstich, W. J. Appl. Nectrochem. 1991, 27, 885-894. Wasmus, S.; Vielstich, W. Nectrochim. Acta 1993, 38, 541-552. Bittins-Cattaneo, B.; Wasmus, S.; Lopez-Mlshima, B.; Vielstich, W. J. Appl. Electrochem. 1993, 23, 625-630. Baltruschat, H.; Beltowska-Brzezinska, M.; Dulberg, A. Nectrochim. Acta 1993, 38, 281-284. Wasmus, S.; Vielstich, W. Electrochim. Acta 1993, 38, 185-189. Jusys, Z.: Liaukonis, J.; Vaskelis, A. J. Nectroanai. Chem. 1992, 325, 247-255. Schmidt, V. M.; Vielstich, W. Ber. Bunsenges. Phys. Chem. 1992, 96, 534-537. Hambitzer, G.; Joos. M.; Schriever, U. DECHEMA Monogr. 1992, 725, 501-509. Fujihira, M.; Noguchi, T. J. Electroanai. Chem. 1993, 347, 457-463. Herron, M. E.; Doyle, S. E.; Roberts, K. J.; Robinson, J.; Walsh. F. C. Rev. Sci. Instrum. 1992, 63, 950-955. Robinson, K. M.; O'Grady, W. E. Rev. Sci. Instrum. 1993, 64, 10611065. Chabala, E. D.; Harii, B. H.; Rayment. T.; Archer, M. D. Langmuir1992, 8, 2028-2033. Yee, H. S.; Abruiia, H. D. Langmuir 1993, 9, 2460-2469. Durand, R.; Faure, R.; Aberdam, D.; Salem, C.; Tourillon, G.; Guay, D.; Ladouceur, M. Nectrochim. Acta 1992, 37, 1977-1982. McBreen, J. J. Nectroanal. Chem. 1993, 357, 373-386. Evans. R. W.: Godfrev. D.: Cowle. B.: Attard. G. A. J. Nectroanal. Chem. l992,'340, 385-37i. Guav, D.: Tourillon, G.; Laoerriere, G.; Belanper. D. J. Phys. Chem. 1992- 96, 7718-7724. Reimers, J. N.; Dahn, J. R. J. Electrochem. SOC. 1992, 739, 2091. Gustafsson. T.; Thomas, J. 0.; Koksbang, R.; Farrington, G. C. Electrochim. Acta 1992. 37, 1639-1643. Herron, M. E.; Pletcher. D.; Walsh, F. C. J. Electroanal. Chem. 1992, 332, 183-197. Druska, P.; Strehblow, H.-H. J. Electroanai. Chem. 1992, 335, 55-65. MacDougall, B.; Graham, M. J.; Davenport, Bardwell, J. A.; Sproule, G. I.; A. J.; Isaacs, H. S. J. Nectrochem. SOC.1992, 739, 371-373. Skotheim, T. A.; Yang, X. Q.; Xue, K. H.; Lee, H. S.; McBreen, J.; Lu, F. Electrochim. Acta 1992, 37, 1635-1637. Bommarito. G. M.; Acevedo, D.; AbruRa, H. D. J. Phys. Chem. 1992, 96, 3416-3419. Robinson, K. M.; Robinson, I.K.; O'Grady, W. E. Electrochim. Acta 1992, 37, 2169-2172. Herron, M. E.; Doyle, S. E.; Pizzini, S.; Roberts, K. J.; Robinson, J.; Hards, G.; Walsh, F. C. J. Electroanai. Chem. 1992, 324, 243-258. Wei, W.; Xie, Q.; Yao, S. J. Electroanai. Chem. 1992, 328, 9-20. Xie, Q.; Wei, W.; Nie, L.; Yao, S. J. Nectroanai. Chem. 1993, 348, 29-47. Wei, W.; Xie, 0 . ;Yao, S.J. Electroanai. Chem. 1992, 334, 1-1 1. '
426R
Analytical Chemistry, Vol. 66, No. 12,June 15, 1994
(161) (162) (163) (164) (165) (166)
(186) (187) (188) (189) (190) (191) (192) (193) (194) (195) (196) (197) (198) (199) (1100) (1101) (1102)
Xie, Q.; Wei, W.; Nie, L.; Yao, S. Anal. Chem. 1993, 65, 1688-1892. Xie, Q.; Shen, D.; Nie, L.; Yao, S. Electrochim. Acta 1993, 38, 22772280. Dong, S.;Xie, Y. J. Nectroanal. Chem. 1992, 335, 197-205. Xie, Q.; Wei, W.; Chen, X.; Nie, L.; Yao, S. J. Electrosnal. Chem. 1993, 357, 91-103. Zamponi, S . ; Czerwinski, A.; Gambini. G.; Marassl, R. J. Electroanal. Chem. 1992, 332, 63-71. Piraud,, C.; Mwarania, E.; Wylangowski, G.; Wilkinson, J.; O'Dwyer, K.; Schiffrin, D. J. Anal. Chem. 1992, 64, 651-655. Kim, S . ; Scherson, D. A. Anal. Chem. 1992, 64, 3091-3095. Olivi, P.; Pereira, E. C.; Longo, E.; Varella, J. A,; BulhBres, L. 0. des. J. Electrochem. SOC. 1993, 740, L81-L82. Anjo, D. M.; Brown, S.; Wang, L. Anal. Chem. 1993, 65, 317-319. Salbeck, J. J. Electroanal. Chem. 1992, 340, 169-195. Salbeck, J. Anal. Chem. 1993, 65, 2169-2173. Shimazu, K.; Yanagida, M.; Uosaki, K. J. Nectroanal. Chem. 1993,350, 321-327. Compton, R. G.; Fisher, A. C.; Wellington, R. G.; Winkler, J. J. Phys. Chem. 1992, 96, 8153-8157. Compton, R. G.; Fisher, A. C.; Wellington, R. G.; Winkler, J.; Bethell, D.; Lederer, P. J. Chem. Soc., Perkin Trans. 2 1992, 1359-1362. Littig, J. S.;Nieman, T. A. Anal. Chem. 1992, 64, 1140-1 144. Fujlwara, T.; Tomlnaga, M. Chem. Lett. 1992, 1217Taniguchi, I.; 1220. Lee, Y. F.: Kirchoff, J. R. Anal. Chem. 1993, 65, 3430-3434. WaRon, D. J.; Phull, S. S.; Bates, D. M.; Lorimer, J. P.; Mason, T. J. Electrochim. Acta 1993, 38, 307-310. Mamantov, G.; Sienerth, K. D.; Lee, C. W.; Coffield, J. E.; Willlams. S. D. J. Electrochem. Soc. 1992, 739, L58-L59. Wang, 2.; Jin, X.; Cai, S.; Liu, Y.; Fujishima, A. Electrochim. Acta 1993, 38, 267-269. Roth, J. D.; Weaver, M. J. Langmuir 1992, 8, 1451-1458. Zippel, E.; Kellner, R.; Krebs, M.; Brelter, M. W. J. Electroanal. Chem. 1992, 330, 521-527. Zhao, M.; Wang, K.; Scherson, D. A. J. Phys. Chem. 1993, 97,44884490. Anderson, M. R.; Huang, J. J. Electroanal. Chem. 1991, 378,335-347. Lin, W.-F.; Sun, S.-G.; Tian, L a . ;Tian, L W . Electrochlm. Acta 1993, 38. 1107-1114. Ogasawara. H.; Sawatari. Y.; Inukai, J.; Ito, M. J. Electroanal. Chem. 1993, 358, 337-342. Faguy, P. W.; Fawcett, W. R.; Liu, G.; Motheo, A. J. J. Electroanal. Chem. 1992, 339, 339-353. Bewick, A.; Gutierrez, C.; Larramona, G. J. Electroanai. Chem. 1992, 333, 165-175. Boonekamp. E. P.; Kelly, J. J.; van der Ven, J.; Sondag, A. H. M. J. Electroanal. Chem. 1993, 344, 187-198. Bewick, A.; Gutierrez, C.; Larramona, G. J. Electroanai. Chem. 1992, 332, 155-167. Zhang, J.; Anson, F. C. J. Electroanal. Chem. 1992, 337, 945-957. Corn, R. M. Electrochim. Acte 1993, 38, 1619-1625. Saez, E. I.; Kitamura, F.; Ohsaka, T.; Tokuda, K. J. Electroanal. Chem. 1993, 353, 323-328. Bauscher, M.; Mantele, W. J. Phys. Chem. 1992, 96, 11101-11108. Krejclk. M.: Danek. M.; Hartl, F. J. Electroanal. Chem. 1991, 377, 179187. Graham, P. J.; Curran, D. J. Anal. Chem. 1992, 64, 2688-2692. Johnson, B. W.; Doblhofer, K. Electrochim. Acta 1993, 38, 895-701. Johnson, B. W.; Bauhofer, J.; Doblhofer, K.; Pettinger, B. Electrochim. Acta 1992, 37, 2321-2329. Budevska, B. 0.; Grifflths, P. R. Anal. Chem. 1993, 65, 2963-2971. Beden, B. J. Nectroanal. Chem. 1993, 345, 1-12. Lopes, M. I.; Fonseca, I.; Olivi, P.; Beden, B.; Hahn, F.; Leger, J. M.; Lamy, C. J. Nectroanal. Chem. 1993, 346, 415-432. Russell, A. E.; Lin, A. S.; O'Grady, W. E. J. Chem. SOC.,Faraday Trans. 1993, 89, 195-198. Russell, A. E.; Williams, G. P.; Lin, A. S.; O'Grady, W. E. J. Electroanal. Chem. 1993, 356, 309-315. Zhang, Y.; Gao, X.; Weaver, M. J. J. Phys. Chem. 1993, 97, 86568683. Zhang, Y.; Weaver, M. J. J. Nectroanal. Chem. 1993, 354, 173-188. Papatheodorou, G. N.; Vayenas, C. G.; Veryklos, X. Kondarkles, D. I.; E . Ber. Bunsenges. Phys. Chem. 1993, 97, 709-720. Mayer, S. T.; Muller, R. H. J. Electrochem. SOC.1992, 739, 426-433. Arsov, L. D.; Kormann, C.; Plieth, W. J. Raman Spectrosc. 1991, 22, 573-575. Pemberton, J. E.: Bryant, M. A.; Sobocinski, R. L.; Joa, S. L. J. Phys. Chem. 1992, 96, 3776-3782. Pemberton, J. E.; Sobocinski, R. L. J. Electroanal. Chem. 1991, 318, 157-169. Joa, S. L.; Pemberton, J. E. J. Phys. Chem. 1993, 97, 9420-9424. Joa, S. L.; Pemberton, J. E. Langmuir 1992, 8, 2301-2310. Sobocinski, R. L.; Pemberton, J. E. Langmuir 1992, 8, 2049-2063. Potahl, G.; Barthelmes. J.; Pleith, W. J. Electroanai. Chem. 1992, 329, 329-338. Davis, K. L.; McGlashen, M. L.; Morrls, M. D. Langmuir 1992, 8, 18541658. Hoke, R. Electrochim. Acta 1993, 38, 947-956. Bukowska, J.; Jakowska, K. J. Nectroanal. Chem. 1992, 322,347356. Ingram, J. C.; Pemberton, J. E. Langmuir 1992, 8, 2034-2039. Ingram, J. C.; Pemberton, J. E. Langmuir 1992, 8, 2040-2048. Bryant, M. A.; Joa, S. L.; Pemberton, J. E. Langmuir1992, 8, 753-756. Barthelmes. J.; Potahl, G.; Plieth, W. J. Electroanai. Chem. 1993, 349, 223-231.
(1103) Saito, H. Bull. Chem. Soc. Jpn. 1993, 66, 963-965. (I 104) De Santana, H.; Temperini, M. L. A.; Rubim, J. C. J. Electroanal. Chem. 1993, 356, 145-155. (1105) Jackowska, K.; Bukowska, J.; Kudelski, A. J. Nectroanal. Chem. 1993, 350, 177-187. (1106) Kudelski, A.; Bukowska, J. J. Mol. Struct. 1992, 275, 145-150. (1107) HIII, W.; Wehling, B. J. fhys. Chem. 1993, 97,9451-9455. (1108) Gao, X.; Zhang, Y.; Weaver, M. J. Langmulr 1992, 8, 668-672. (1109) Turcotte, S. 6.; Benner, R. E.; Riley, A. M.; Li, J.; Wadsworth, M. E.; Bodily, D. M. J. Electroanal. Chem. 1993, 347, 195-205. (1110) Oyama, M.; Okada, M.; Okazaki, S. J. Elecfroanal. Chem. 1993, 346, 261-290. (1111) Lee, S. 6.; Kim, K.; Kim, M. S. J. fhys. Chem. 1992, 96,9940-9943. (1112) Lacconi, 0.; Reents, 6.; Plieth, W. J. Electroanal. Chem. 1992, 325, 207-217. (1113) Son. Y.; de Tacconi. N. R.; Raleshwar, K. J. Electroanal. Chem. 1993. 345, 135-146. (1114) Melendres, C. A.; Pankuch, M. J. Electroanal. Chem. 1992, 333,103113. (1115) Shi, C.; Zhang, W.; Lombardl, J. R.; Birke, R. L. J. fhys. Chem. 1992, 96,10093-10096. (1116) Misono, Y.; Shibasakl, K.; Yamasawa, N.; Mineo, Y.; Itoh, K. J. fhys. Chem. 1993, 97,6054-6059. ( I 1 17) Palys, B. J.; Puppeis. G. J.; van den Ham, D.; Feii, D. J. Electroanal. Chem. 1992, 326, 105-112. (1118) Simonet, J.; El Badre, M. C.; Cariou, M. J. Electfoanal. Chem. 1992, 334, 169-182. (1119) Ei Badre, M. C.; Cariou, M.; Simonet. J. J. Electroanal. Chem. 1992, 327, 185-200. (1120) Gourier, D.; Tranchant, A.; Baffier, N.; Messina, R. Nectrochim. Acta 1992. 37,2755-2764. (1121) Dunsch. L.; Petr, A. Bef. Bunsenges. fhys. Chem. 1993,97,436-439. (1122) Slerak, P. J.; Wieckowski, A. J. Electroanal. Chem. 1992, 339,401410. (1123) Sendlfer, M. E.; Zhao, M.; Kim, S.; Scherson, D. A. Anal. Chem. 1993, 65, 2093-2095. (1124) Hamnett. A. J. Chem. SOC.,Faraday Trans. 1993, 789, 1593-1607. (1125) Chao, F.; Costa, M.; Tadjeddine. A. J. Electroanal. Chem. 1992, 329, 3 13-327. (1126) Hillier, A. C.; Ward, M. D. Anal. Chem. 1992, 64, 2539-2554. (1127) Bacskai, J.; LangG.; Inzelt, G. J. Electroanal. Chem. 1991,379,55-69. (1128) Beck, R.; Pittermann, U.; Weii, K. G. J. Nectrochem. SOC.1992, 739, 453-46 1. (1129) Lee, W.-W.; White, H. S.; Ward, M. D. Anal. Chem. 1993, 65,32323237. (1130) olidl& A.; Hillman, A. R.; Bruckenstein, S. J. Electroanal. Chem. 1991, 378. 411-420. (1131) Heusler, K. E.; Pietrucha, J. J. Electroanal. Chem. 1992, 329,339-350. (1132) Dusemund, C.; Schwftzgebel, G. Ber. Bunsenges. fhys. Chem. 1991, 95,1543-1546. (1133) Lin, 2.; Ylp, C. M.; Joseph, I. S.; Ward, M. D. Anal. Chem. 1993. 65, 1546-1551.
J. INSTRUMENTATION (Jl)
Gabrieili, C.; Huet, F.; Keddam, M. J. Electrochem. SOC. 1991, 138, L82-L84.
Amatore. C.; Lefrou, C. J. €lectroanal. Chem. 1992, 324,33-58. Yamagishi, H. J. Nectroanal. Chem. 1992, 326, 129-137. Fidler, J. C.; Penrose, W. R.; Bobis, J. P. I€€€ Trans. Instrum. MS. 1992, 41, 308-310. Senaratne, C,; Hanck, K. W. Anal. Instrum. 1992, 20, 1-22. Popkkov, G. S.; Schlndler, R. N. Rev. Sci. Instrum. 1992, 63. 53665372. Schefold, J. J. Elechoanal. Chem. 1992, 341. 111-136, 225-233. Clark, S. R.; Paul. D. W.; Sundgren, H. Microchem. J. 1992, 46, 225233. Dygas, J. R.; Fafiiek, G.; Durakpasa, H.; Brelter, M. W. J. Appl. Electrochem. 1993. 23,553-558. Cruaiies, M. T.; Drlckamer, H. G.; Faulkner, L. R. J. fhys. Chem. 1992, 96. 9888-9892. Sachinidis, J.; Shalders, R. D.; Tregloan, P. A. J. Electroanal. Chem. 1992, 327,219-234. Van Manen, P.A.; Weewer, R.; dew%,J. H. W. J. Electrochem. SOC. 1992, 739,1130-1 134. Sorrels, J. W.; Dewald, H. D. Electroanalysis 1992, 4 487-493. Hua, C.; Sagar, K. A.; McLaughlin, K.; Jorge, M.; Meanay, M. P.; Smyth, M. R. Analyst 1991, 716, 1117-1120. Igawa, M.; Takabayaski, Y.; Koizumi, T. Bull. Chem. SOC.Jpn. 1992, 65, 1561-1565. Hevrovska. R. J. fhvs. Chem. 1993. 9. 1962-1964. Zeyer, C.; Gruniger, H. R.; Dossenbach, 0. J. Appl. Electrochem. 1992, 22. 304-305. Kahnsky, A.; Willner, I.; Mandler, D. J. Nectrochem. SOC.1993. 740, L25-L27. Dueber, R. E.; Dickens, P. 0. J. Nectrochem. SOC.1991, 738,L79-L80. Jermann, R.; Tercier, M.-L.; Buffie, J. Anal. Chim. Acta 1992, 269, 49-58. Mldgley. D. Analyst 1993, 178,41-45. Moussy, F.; Harrison, D. J.; O'Brien, D. W.; Rajotte, R. V. Anal. Chem. 1993, 65,2072-2077. Watson. S . W.: Madsen. B. W. Corroslon 1992. 48. 727-733. Malem, F.; Mandler, D. J: Nectrochem. SOC.1992, 139,L65. Gutz, I. G. R.; Angnes, L.; Pedrotti, J. J. Anal. Chem. 1993, 65,500503. Pedrotti, J.; Angnes, L.; Gutz, I. G. R. Nectroanalysls (N.Y.) 1992, 4, 635-642. Aidstadt, J. H.; Dewald, H. D. Anal. Chem. 1992, 64, 3176-3179. Tierney, M. J.; Kim, H.-0. L. Anal. Chem. 1993, 65,3435-3440. 305-31 1.H.; Tanaka, H.; Baba, N. Bull. Chem. SOC.Jpn. 1993, 66, Masuda, Tang, T. K. L.; Chan, K.-Y. J. Electmanal. Chem. 1992, 334,65-80. Powell, B. R. Catal. Len. 1992, 75,189-197. Coeuret, F. J. Appl. Electrochem. 1993, 23,853-855. Popkirov, G. S.J. .€lectroanal. Chem. 1993, 359,97-103. Kounaves, S. P.; Lu, D. D. Comput. Chem. 1992, 76. 29-33. Liao, S.-L.; Olson, C. L. Rev. Sci. Instrum. 1993, 64, 1809-1814. Andrieux, C. P.; Delgado, G.; Saveant, J.-M.; Su, K. B. J. Elechoanal. Chem. 1993, 348, 107-121.
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