UPCOMING RESEARCH Determination of Tin in Copper by Radiochemical Proton Activation Analysis The method is capable of certifying the tin content in two reference materials a t the sub μg/g level. Karel Strijckmans*, Wald Lodewyckx, Jacques Dewaele, and Raichard Dams, Laboratory of Analytical Chemistry, In stitute for Nuclear Sciences, Universiteit Gent, Proeftuinstraat 86, B-9000 Gent, Belgium Development of Submicron Chemical Fiber Optic Sensors Extremely small fiber optic sensors are prepared by photopolymerization of submicron fiber tips. The pH sen sors exhibit millisecond response times a s well as good reversibility, reproducibility, and stability. Weihong Tan, Zhong-You Shi, and Raoul Kopelman*, De partment of Chemistry, The University of Michigan, Ann Arbor, MI 48109 Analytical Spectroscopy and Structure of Biomolecules Using an ab Initio Computational Method An ab initio computational method is used to study t h e spectroscopic properties of biologically important phenethylamine and its derivatives. The IR and Raman spec tra, ionization potentials, electron affinities, and charge density distributions are discussed. Yeong Choi and David M. Lubman*, Department of Chemis try, The University of Michigan, Ann Arbor, MI 48109 Self-Modeling Mixture Analysis of Second-Derivative Near-Infrared Spectral Data Using the SIMPLISMA Approach When second-derivative spectra are used a s an interme diate step, pure variable-based self-modeling mixture analysis can be used for data without unique spectral re gions. W. Windig* and D. A. Stephenson, Analytical Technology Di vision, Eastman Kodak Company, Rochester, NY 14652-3712 Separation of Closely Related Large Peptides by Micellar Electrokinetic Chromatography with Organic Modifiers Although large peptides with almost identical electrophoretic mobilities cannot be separated by CZE or con ventional MEKC, they are successfully separated by us ing MEKC with organic modifiers. Toshiyuki Yashima*, Akihiro Tsuchiya, and Osamu Morita, Pharmaceutical Research Laboratories, Kyowa Hakko Kogyo Company Ltd., 1188, Shimotogari, Nagaizumi-cho, Sunto-gun, Shizuoka 411, Japan and Shigeru Terabe, Department of Materials Science, Faculty of Science, Himeji Institute of Technology, Kamigori, Hyogo 678-12, Japan
Computer Simulation and Experimental Validation of the Electrophoretic Behavior of Proteins. 2. Model Improvement and Application to Isotachophoresis The computer-predicted electrophoretic behavior of pro teins more accurately corresponds to experimental data when a realistic approach for the contribution of a pro tein to ionic strength is adopted. Richard A. Mosher, Center for Separation Science, University of Arizona, Tucson, AZ 85721 and Petr Gebauer, Jitka Caslavska, and Wolfgang Thonnann*, Department of Clini cal Pharmacology, University of Berne, Murtenstrasse 35, CH3010 Berne, Switzerland Simultaneous Measurement of the Atomic and Molecular Absorption of Aluminum, Copper, and Lead Nitrate in an Electrothermal Atomizer Few molecular species are observed for Cu(N0 3 ) 2 . PbO is seen before the appearance of atomic Pb, and Pb 2 appears concurrent with atomic Pb during t h e atomization of Pb(NO a ) 2 . The atomization of A1(N0 3 )3 produces many unidentified molecular species. Judy Ratliff and Vahid Majidi*, Department of Chemistry, University of Kentucky, Lexington, KY 40506 Axial Evolution of the Negative Glow in a Hollow Cathode Discharge The temporal evolution of the discharge in a hollow cath ode is reported. Implications for analytical applications using the hollow cathode discharge in the pulse are dis cussed. Robert B. Bartlow and Steven T. Griffin, Department of Electrical Engineering, Memphis State University, Memphis, TN 38152 and J. C. Williams*, Department of Chemistry, Memphis State University, Memphis, TN 38152 Mass Spectrometric Analysis of Rubber Vulcanizates by Laser Desorption/Laser Ionization Laser desorption followed by laser ionization MS is used to analyze vulcanized rubbers. Different wavelengths for the post-ionization step allow selectivity to detect vari ous additives present. Keith R. Lykke*, Deborah Holmes Parker, Peter Wurz, Jerry E. Hunt, Michael J. Pellin, Dieter M. Gruen, and John C. Hemminger, Materials Science and Chemistry Divi sions, Argonne National Laboratory, Argonne, IL 60439 and De partment of Chemistry, University of California, Irvine, CA 92717, and Robert P. Lattimer, The B. F. Goodrich Co., Re search & Development Center, Brecksville, OH 44141-3289
These articles are scheduled to appear in AC RESEARCH in the n e a r future. "•"Corresponding author ANALYTICAL CHEMISTRY, VOL. 64, NO. 21, NOVEMBER 1, 1992 · 1003 A
UPCOMING RESEARCH Equivalence of Staircase and Linear Sweep Voltammetries for Reversible Systems Including Conditions of Convergent Diffusion Accurate numerical calculations indicate that, for reversible systems, staircase voltammetry becomes equivalent to linear sweep voltammetry when current is sampled 3/10 of the way along the step. Uruthirapasupathy Kalapathy and Dennis E. Tallman*, Department of Chemistry, North Dakota State University, Fargo, ND 58105-5516 Characterization of a Gold Minigrid Cell for Fourier Transform Infrared Spectroelectrochemistry: Experimental vs Digitally Simulated Response Digital simulation of potential step experiments provides a m e a n s to determine t h e experimental minigrid-to prism distance. With this cell and an MCT detector, IR spectra can be obtained with potential sweep rates up to 200 mV/s. Philip B. Graham and David J. Curran*, Department of Chemistry, University of Massachusetts, Amherst, MA 01003
Horizontal Polymerization of Mixed Trifunctional Silanes on Silica: A Potential Chromatographic Stationary Phase A design for surface bonding of monolayers, potentially applicable to chromatographic stationary phases, is reported. The design combines the superior hydrolytic stability of self-assembled monolayers with the selectivity and reproducibility of monomeric stationary phases. Mary J. Wirth* and Hafeez O. Fatunmbi, Department of Chemistry & Biochemistry, University of Delaware, Newark, DE 19716 Solid-Phase Method for the Purification of DNA Sequencing Reactions A solid-phase method for purification of t h e singlestranded DNA molecules produced in enzymatic sequencing reactions is developed. The method is used to investigate the effect of various contaminants on DNA sequence data. Xinchun Tong and Lloyd M. Smith*, Department of Chemistry, University of Wisconsin, Madison, WI 53706 Flow Electroanalysis of Compound Semiconductor Thin Films: Application to the Compositional Assay of Cathodically Electrosynthesized Cadmium Selenide
Two-Dimensional Conductometric Detection in Ion Chromatography. Postsuppressor Conversion of Eluite Acids to a Salt Simultaneous cation and anion exchange of eluite acids to LiF in a membrane-based device greatly increases the sensitivity for t h e detection of weak acids in a suppressed anion chromatography system. Ingemar Berglund and Purnendu K. Dasgupta*, Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409-1061
A combination of chemical and electrochemical stripping of CdSe + Se + Cd from t h e support Ti electrodes is used in a flow electroanalysis scheme that is chemical state selective in that free elements and those present as CdSe are differentiated. Noseung Myung, Chang Wei, and Krishnan Rajeshwar*, Department of Chemistry, Box 19065, The University of Texas at Arlington, Arlington, TX 76019-0065 252
Acridinium Chemiluminescence Detection with Capillary Electrophoresis
Cf Plasma Desorption Mass Spectrometry in the Synthesis of Porphyrin Model Systems 252
An interface for evaluating the use of chemiluminescence detection with capillary electrophoresis is developed. Effects of reaction conditions on detector response are investigated, and detection limits in t h e low femtomole to attomole range are possible. Michael A. Ruberto and Mary Lynn Grayeski*, Department of Chemistry, Seton Hall University, South Orange, NJ 07079
Cf PDMS provides rapid characterization of a few nmol of porphyrin samples. Near-universal applicability is illustrated by determination of 114 compounds of diverse structures and masses from 700 to 3000 u. Jonathan S. Lindsey*, Department of Chemistry, Carnegie Mellon University, 4400 Fifth Ave., Pittsburgh, PA 15213 and Tanuja Chaudhury and Brian Chait, The Rockefeller University, New York, NY 10021
Pyrrole Copolymerization and Polymer Derivatization Studied by X-ray Photoelectron Spectroscopy
Determination of Intracellular Species at the Level of a Single Erythrocyte via Capillary Electrophoresis with Direct and Indirect Fluorescence Detection
Nitro-functionalized polypyrroles are obtained by copolymerization of pyrrole or derivatization of polypyrrole through the amino functionality. The stability of the nitro substituents is monitored using XPS. Stephen J. Vigmond, Krishna M. R. Kallury, and Michael Thompson*, Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, Canada M5S 1A1
Glutathione and simple cations are quantified in single erythrocytes by microderivatization and indirect fluorometry, respectively, at t h e subfemtomole level. Barry L. Hogan and Edward S. Yeung*, Department of Chemistry and Ames Laboratory-USDOE, Iowa State University, Ames, IA 50011
ANALYTICAL CHEMISTRY, VOL. 64, NO. 21, NOVEMBER 1, 1992 · 1005 A
