Liquid Chromatography: Theory and Methodology - ACS Publications

Anal. Chem. 1996, 68, 515R-568R

Liquid Chromatography: Theory and Methodology John G. Dorsey* and William T. Cooper

Department of Chemistry, Florida State University, Tallahassee, Florida 32306-3006 Barbara A. Siles

Department of Chemistry, College of William and Mary, Williamsburg, Virginia 23187-8795 Joe P. Foley

Department of Chemistry, Villanova University, Villanova, Pennsylvania 19085-1699 Howard G. Barth

Central Research and Development Department, E. I. du Pont de Nemours & Company, P. O. Box 80228, Experimental Station, Wilmington, Delaware 19880 Review Contents Books, Reviews, and Symposia Proceedings Theory and Optimization Theory Optimization Data Analysis Stationary Phase Classification Retention/Solute-Stationary Phase Interactions Modeling/Peak Characterization/Smoothing Calibration and Curve Fitting Deconvolution Factor Analysis Miscellaneous Fundamental Studies Pharmacological and Biological Applications Normal Phase Reversed-Phase Mobile Phase Studies Stationary-Phase Studies Biopolymer Separations Column Packings Reversed Phase Hydrophobic and Hydrophilic Interaction Chromatography Ion Exchange Preparative Liquid Chromatography of Biopolymers Affinity Chromatography Reviews and Theoretical Models Affinity Chromatography Stationary-Phase Supports Affinity Elution Conditions Ligand Immobilization and Applications Ion Chromatography Mobile-Phase and Sample Effects Stationary Phases Suppressor Technology, Quantitation, and Detection Secondary Chemical Equilibria Reviews Micellar Liquid Chromatography Acid/Base Equilibria Complexation Equilibria Ion-Pairing Interaction Optical and Positional Isomers S0003-2700(96)00020-0 CCC: $25.00

515R 516R 516R 517R 520R 520R 521R 521R 521R 521R 521R 521R 522R 522R 523R 524R 525R 527R 527R 529R 531R 531R 532R 532R 532R 533R 534R 534R 535R 536R 536R 537R

Reviews New Chiral Stationary Phases Liquid-Phase Additives/Derivatization Theory/Mechanism/Method Development Geometric Isomers Multidimensional Chromatography and Column Switching Preparative LC Reviews Theory/Optimization/Methodology Packings/Columns/Hardware Selected Applications Pre- and Postcolumn Derivatization Microcolumn and Open Tubular LC Trace Analysis Physiochemical Measurements Partition Coefficients/Hydrophobic Measurements Association and Stability Constants Thermodynamic Studies Kinetic Studies Conformational Studies Literature Cited

543R 544R 545R 546R 546R 547R 549R 549R 549R 549R 549R 550R 552R 553R 553R 553R 554R 555R 555R 556R 557R

This review covers fundamental developments in liquid chromatography during the period of approximately October 1993 through October 1995. As with the past three issues of the Fundamental Reviews, there are separate reviews on instrumentation and on size exclusion chromatography; this review is of important developments in the chemistry of the separation process. The primary searching method for this work has been CAS online, and each author has supplemented these with search methods of their own. This is not meant to be a comprehensive review of all published papers during this time period; rather, we have tried to select those papers which we feel are significant developments. We have largely restricted the covered material to the English language literature. Comments and suggestions concerning this review are welcomed and encouraged and should be sent to the first author (J.G.D.; e-mail, [email protected]).

537R 537R 538R 539R 540R 541R 543R

BOOKS, REVIEWS, AND SYMPOSIA PROCEEDINGS First, the previous Fundamental Review covered work occurring approximately from October 1991 through October 1993 and

© 1996 American Chemical Society

Analytical Chemistry, Vol. 68, No. 12, June 15, 1996 515R

was published during this review period (A1). Many other specialized reviews were published, and they will be cited during the respective sections of this review. Three somewhat general books were published on the general topic of liquid chromatography. Scott authored a work Liquid Chromatography for the Analyst (A2), Riley et al. edited a book Pharmaceutical and Biomedical Applications of Liquid Chromatography (A3), and Subramanian edited a work Process Scale Liquid Chromatography (A4). Several other more specialized texts were also published, and where appropriate, they are referenced in the individual sections later in this review. Many symposia proceedings were published also, as is customary for many of the yearly chromatography meetings, and again, individual papers from these are referenced in the individual sections. It has become much more common for these proceedings to be published as part of the open literature in journals such as Journal of Chromatography, and it is not necessary to duplicate their references here. THEORY AND OPTIMIZATION Theory. With the exception of the reviews cited immediately below, we have excluded nearly all theoretical contributions that can logically be placed in another category elsewhere in this review (e.g., reversed phase, geometric and optical isomers, preparative, etc.), especially those contributions pertaining to chromatographic properties (efficiency, retention, selectivity). Reviews. Hwang reviewed the advancement of dynamic theories based on wave propagation phenomena for fixed-bed sorption processes such as chromatography and countercurrent mass-transfer processes such as distillation, using a mathematical notation common to both classes. The review covers the equilibrium theories of multicomponent chromatography with emphasis on the coherent wave theory originated by Helfferich and the most recent attempts to apply this theory to multicomponent countercurrent processes (B1). Thoemmes and Kula reviewed membrane chromatography, an integrative technology for the purification of proteins introduced several years ago. Its main advantage, the absence of pore diffusion, which occurs in conventional chromatographic columns using porous particles, is achieved by attaching the active ligands to the inner surface of the through pores of microfiltration membranes, where mass transport takes place mainly by convective flow (B2). Lightfoot et al. described the use of NMR techniques for monitoring the progress of chromatographic separations and for aiding in the design of such systems (B3). Hayashi and Matsuda discussed uncertainty structure, information theory, and optimization of quantitative analysis from the perspective of separation science. The optimum for quantitation was defined as the set of the operating conditions that provides the highest precision (or the lowest relative standard deviation) among all the examined conditions and could often be located through error prediction (B4). Forgacs and Cserhati reviewed the retention strength and selectivity of porous graphitized carbon columns, including the properties of these supports, the mechanisms of retention, and applications, and suggested solvent combinations for typical separations (B5). Hagan provided a tutorial from the perspective of hospital pharmacists on the fundamentals of high-performance liquid chromatography (HPLC) in small-scale studies of drug stability (B6). Scott reviewed various aspects of rate (kinetic) theory for liquid column chromatography 516R

Analytical Chemistry, Vol. 68, No. 12, June 15, 1996

(B7). Finally, Davis reviewed statistical theories of peak overlap in one-dimensional or multidimensional separations such as TLC, electrophoresis, or capillary chromatography (B8). A number of theoretical reviews appeared in a special issue of the Journal of Chromatography devoted to reversed-phase liquid chromatography (RPLC), with almost all of the effort focused on retention. Carr et al. reexamined the driving forces for retention and showed that (i) most of the free energy of retention in RPLC arises from net attractive (exoergic) processes in the stationary phase, and not from net repulsive (endoergic) processes in the mobile phase; (ii) variations in retention upon changing the mobile phase are dominated by alterations in the net processes in the mobile phase; and (iii) regular solution theory is a grossly inadequate model of interactions in water and hydroorganic mixtures and should not be used to model retention in aqueous mobile phases (B9). Tijssen et al. first reviewed possibilities and shortcomings of regular solution theories and then several lattice models for the description of partitioning/adsorption and retention in RPLC. Among their conclusions was that the nature of the grafted layer [e.g., flexibility of grafted chains and phase transitions, geometrical effects, chain length effects, chain branching and surface effects (coverage and hydroxyls)] indeed influences the adsorptive and retentive capacity of the bonded stationary layer (B10). Valko et al. examined retention in RPLC as a function of binary-solvent mobile-phase composition, comparing various empirical and theoretical equations proposed to explain this dependence. Because the functional dependence of k′ on organic modifier content varies from system to system, the authors were unable to draw any overall conclusions as to the nature of the retention process (B11), in contrast to the prior two studies. Finally, Jandera reviewed a simple semiempirical retention model for RPLC based on interaction indexes, in which the polarities and the concentrations of the mobile-phase components and the molar volume and polarity (interaction index) of the solute are assumed to be the major factors controlling the retention (B12). The model can quantitatively describe the retention of homologs and oligomers and explain and predict conditions under which some polar oligomers are eluted in order of decreasing molecular mass. Wheeler et al. reviewed the measurement and observation of phase transitions that RPLC stationary phases can undergo, including the implications of such transitions in the rational design of improved reversed-phase separations (B13). Lochmueller et al. reviewed and compared the relative merits of three approaches to the prediction of retention: (i) methods utilizing a physical model, (ii) methods which assume no model, and (iii) methods with an abstract or hidden model (B14). Sun et al. reported a critical review of the general concept of the solubility parameter and several empirical and semiempirical equations which utilize one or more forms of it for the prediction of solute retention (B15). Finally, Kaliszan briefly summarized the theoretical background of quantitative structure/retention relationships (QSRRs) before discussing several relevant RPLC separation theories more extensively (B16). He also reviewed QSRR with respect to chromatographic determination of hydrophobicity of drugs and xenobiotics (B17). General Information. Yun et al. described important theoretical relationships between the void volume, mobile-phase volume, retention volume, adsorption, and Gibbs free energy in HPLC, SFC, and GC. In each of these cases, the measured column

volumes determined the exact type of capacity factor obtained, the type of adsorption measured, and the experimentally determined volume of the adsorbed phase. Experimental methods are also discussed for the accurate determination of the entire amount or volume of eluent in a column, the void volume, the total amount of material adsorbed, and the excess amount of material adsorbed (B18). Lowrey and Famini described theoretical linear solvation energy relationships (LSERs) that can serve as replacements to the empirical LSERs of Kamlet and Taft and subsequently be used in QSRRs (B19). Boehm and Martire reported a theory of homopolymer retention for the case where weak polymer adsorption and/or sorption prevails in the stationary phase; values of the solvent strength parameter S for different chromatographic systems are discussed within the framework of the theory (B20). Waite et al. studied the sorption/desorption kinetics of anionic and neutral probes on silica and methylated silica (B21) surfaces using temperature-jump relaxation measurements. Although the adsorption rates of two neutral probes on silica were indistinguishable from a diffusion-limited rate (indicating a negligible barrier to sorption), the adsorption rate of an anionic fluorescent probe, 8-anilino-1-naphthalenesulfonate (ANS), was slower than the diffusion-limited rate and exhibited a significant influence over the equilibrium constant. On methylated silica, in the absence of electrolyte, the relaxation signal for ANS was biexponential, consistent with a postulated two-site sorption isotherm. In the presence of electrolyte, the relaxation signal for ANS was a single exponential, consistent with a linear adsorption isotherm. Moreover, the adsorption rate and equilibrium constant increased significantly with added electrolyte, which showed that adsorption kinetics can influence both band broadening and retention. Bahowick and Synovec developed a simple model that predicts quantitation precision for the analysis of poorly resolved peaks as a function of resolution and retention time precision and showed that shorter columns, because they provide improved retention time precision and higher S/N ratios, can often provide more precise (and rapid) quantitation (B22). The advantages in quantitation with short columns are also applicable to GC, supercritical fluid chromatography (SFC) and possibly to capillary electrophoresis (CE). Lukulay and McGuffin extended the concept and theory of solvent modulation to serially coupled columns, separating isomeric polynuclear aromatic hydrocarbons using octadecylsilica and β-cyclodextrin silica stationary phases with aqueous methanol and acetonitrile mobile phases (B23). Horka et al. examined capillary column performance in reversed-phase parallel-current open-tubular liquid chromatography (LC) with a cyclohexanol/water mobile phase and compared the plate heights obtained with those predicted by the Golay equation (B24). Lee and Olesik compared enhanced-fluidity and/ or elevated-temperature mobile phases in RPLC with respect to to efficiency, analysis time, and selectivity. Improvements in efficiency and analysis time were observed in the order of room temperature methanol/water < elevated temperature < enhanced fluidity (methanol/water/CO2) < combined elevated temperature/ enhanced fluidity. Unfortunately, the selectivity decreased in this same order, and sometimes at a greater rate (B25). Ion Exchange. Dolgonosov considered the theoretical possibility of a new class of separation sorbents having the structure of a centrally localized ion exchanger for highly efficient ion chromatography separations, including an outline of the principles

of the synthesis of centrally localized ion exchangers and the properties of representative sorbents (B26). Luo and Hsu employed a mathematical model which takes into account the combined effects of axial dispersion, film mass-transfer resistance, intraparticle diffusion, and adsorption equilibria to simulate the gradient elution process in a diethylaminoethyl ion-exchange column for the purification of proteins. Both the individual and combined effects of (i) intraparticle diffusivity, (ii) adsorbent particle diameter, and (iii) gradient steepness slope on the resolution of β-lactoglobulin A and β-lactoglobulin B were investigated. The authors suggested a general strategy for the design and optimization of gradient elution processes for biochemical separations (B27). Nonlinear Chromatography. Kalinitchev described the effects of nonlinearity on a number of properties in multicomponent chromatography (B28). Frey et al. developed a general numerical method for multicomponent chromatography for the case where a pH gradient occurs and several buffering species are present that become adsorbed together with the components being separated through an ion-exchange mechanism (B29). The method accounts for the adsorption of each ionic form of each buffering species, for multicomponent diffusional interactions arising from induced electrical fields, for volume and concentration overloading of proteins, and for changes in the adsorption capacity caused by pH variations. Numerical calculations illustrate factors governing the selection of the adsorbent and buffer components for use in separating mixtures of protein using retained, internally generated pH gradients. Fornstedt and Guiochon examined theoretically (B30) and experimentally (B31) the elution profiles of high-concentration elution bands and large system peaks. Both additive and solute individual profiles were recorded separately, using a diode-array detector operating at different wavelengths selected for the selectivity of the response to the two different compounds. The recorded profiles were in very good agreement with the profiles calculated from the isotherms of the two compounds, using the equilibrium dispersive model of chromatography. In a related study, Guan et al. evaluated the measurement of single-component isotherms by the elution by characteristic point (ECP) method (B32). The ECP method was recommended only when the column efficiency exceeded 2000 theoretical plates; otherwise, the direct method of determination of the isotherm from the band profile based on the numerical solution of the inverse mathematical problem was more accurate. Firouztale’ et al. utilized and validated a dynamic “rate-based” mathematical model of a chromatographic column that accounts for axial dispersion, liquid film mass transfer, and pore diffusion coefficients and incorporates a Langmuir nonlinear isotherm to predict breakthrough behavior of cephalosporin C on columns of Amberchrom reversed-phase media under several different conditions (B33). Optimization. Reviews. Hayashi and Matsuda reviewed the optimization of quantitative analysis in separation science, taking into account most if not all factors of the separation and measurement process (B4). Martin reviewed the optimization of countercurrent chromatography solvent systems (B34). Gennaro reviewed reversed-phase ion-pair and ion-interaction chromatography, their retention mechanisms, and chemometric methods for their optimization (B35). Sander and Wise reviewed shape selectivity in RPLC for the separation of planar and nonplanar solutes, with an emphasis on practical choices that are available Analytical Chemistry, Vol. 68, No. 12, June 15, 1996

517R

to control selectivity and optimize separations for isomers and related mixts (B36). Schoenmakers and Tijssen reviewed retention models for ionogenic solutes as a function of pH for optimization purposes (B37). Limitations of the theoretical model (sigmoidal) curve and possible causes of deviations are discussed, as well as the inaccuracies introduced by linearly or quadratically interpolating part of a sigmoidal curve and the sensitivity of sigmoidal interpolation to experimental errors; a few key references were unfortunately omitted. General Information. Vanbel et al. described criteria for chromatographic ruggedness based on derivatives of other response functions (typically resolution-based criteria) that allows it to be included explicitly as an objective in systematic method development. Three multicriteria decision-making (MCDM) procedures were consideredsPareto-optimality (PO) plot, Derringer’s desirability function, and the multiple-threshold approach (MTA)sfor the optimization of pH and solvent composition (B38). Using the maximum principle approach and the mathematical programming approach, Wang and Yu conducted control studies for the determination of the optimal ionic strength gradient in gradient elution linear chromatography (GELC) of proteins with and without time lags in control functions (B39). Numerical computations show that the resolution and throughput can be maximized by adopting the optimal inlet gradient profiles. Guillaume and Guinchard used benzodiazepines as model compounds in a number of optimization studies. First, they reported a new response function which provided the most efficient separation of 10 benzodiazepines, comparing their results with those obtained via a different optimization method (B40). Guillaume and Guinchard then compared two different methods for the measurement of the separation factor R of a critical pair of benzodiazepines at different temperatures. Differences in the trends of ∆(∆G), ∆(∆H), and ∆(∆S) with increasing organic solvent were observed for methanol/water and ACN/water mobile phases, suggesting a significantly different retention mechanism (B41). They also optimized the separation of 10 benzodiazepines using as variables temperature, flow rate, and mobile-phase composition. ∆(∆G), ∆(∆H), and ∆(∆S) for a critical pair of benzodiazepines were determined from ln R vs reciprocal temperature plots after a rapid chemometric methodology was employed to determine the separation factor, R, at different temperatures (B42). The same thermodynamic approach to optimization was employed for the separation of seven p-hydroxybenzoic esters (B43). Finally, Guillaume and Guinchard used a special polynomial function derived from 13 preliminary experiments to simultaneously optimize HETP and resolution for seven compounds via the mobile-phase composition, flow rate, and column temperature (B44). Fischer and Jandera used four-parameter equations to (i) account for the retention of and (ii) optimize the selectivity for phenylurea compounds on nitrile- and amino-bonded stationary phases over a broad composition range of 2-propanol/n-hexane and 2-propanol/water mobile phases (B45). Chaminade et al. described flexible computer algorithms for iterative solvent strength optimization. Linear retention models developed from the data of two gradient runs can be extended to a more accurate quadratic model from additional experiments (B46). Using a fiveparameter model, Marengo et al. simultaneously optimized the flow rate and the concentration and chain length of the ioninteraction reagent for the determination of azide by RP-IPC. The 518R


model explained 98.21% of the variation in the data, and the optimized detection limit for sodium azide was 6.0 ppb (B47). Hancock et al. investigated temperature as a variable in RPLC for the separation of several peptide and protein samples and found that the simultaneous variation of temperature and gradient steepness was a convenient and effective means of varying selectivity and controlling band spacing (B48, 49). Computer simulations were useful in both interpreting the experiments and optimizing the final separations. Preparative. Jennings et al. noted that the optimization of process efficiency in the preparative separation and purification of biochemical and pharmaceutical products is a highly nonstandard control problem, with three unique characteristics: (i) the process contains a set of interrelated subprocesses with different time or space intervals; (ii) the min-max objective function is not in the conventional form; and (iii) state-dependent time lag appears in the control variables. With this understanding, the authors employed the control parametrization technique to optimize the ionic strength gradient in an affinity chromatographic system (B50). Felinger and Guiochon, using the numerical solution of the equilibrium-dispersive model of chromatography and a nonlinear simplex algorithm, calculated optimum experimental conditions and column design parameters for the most economical preparative separation of binary mixtures, with an emphasis on solvent consumption and capital costs. Solvent consumption depended only on the column efficiency, the retention factor, and the loading factor whereas the production rate depended on particle size, column length, mobile-phase flow velocity, and retention and loading factors. A hybrid objective response function was constructed to evaluate the trade-offs between the production rate and the solvent consumption (B51). Suwondo et al. used a simulation model of a chromatographic separation to define either of two objective functions, product recovery (to be maximized) or off-cut collection (to be minimized), which are then optimized by transforming an optimal control problem into a nonlinear programming problem (B52). Two numerical examples were presented: the separation of a binary mixture and the purification of one key component in a ternary mixture. Gallant et al. presented a systematic method of selecting the optimum step gradient program under conditions of high-mass loading in preparative ion-exchange chromatographic where nonlinear adsorption isotherms are expected; good agreement was observed between simulated and experimental step gradient separations of the proteins R-chymotrypsinogen A, cytochrome c, and lysozyme (B53). Using steric mass action (SMA) formalism to describe the multicomponent nonlinear adsorption of proteins and polyelectrolytes in cation-exchange displacement chromatography, they also showed (B54) both theoretically and experimentally that (i) significantly higher throughputs can be achieved by operating protein displacement systems under nondeveloped conditions and (ii) the development of the displacement condition proceeds faster at lower salt concentration, indicating that a reduction of the carrier salt concentration can increase the productivity of displacement systems even further. Solute Property-Based Optimization. Hamoir and Massart outlined a strategic two-stage approach for method selection in HPLC. Four chromatographic modes [reversed phase (RP), normal phase (NP), gradient elution, and ion pair] were evalauted on the basis of the solutes’ acid/base properties and hydrophobicity (log P value, or total number of carbons). Following their

evaluation (first choice, second choice, or inappropriate), initial solvent strength conditions (RP and NP) were identified on the basis of a structure/retention relationship (B55). Fekete et al. used a commercial expert system, EluEx, that predicts the optimum eluent starting composition in RPLC based on solute pKa’s (where applicable) and log P’s (logarithm of 1-octanol/water partition coefficients), which in turn are estimated from solute structure, for the separation of neutral, acidic, and basic solutes (B56). Optimum binary eluent compositions are usually obtained after only two or three experiments, although the expert system did not account sufficiently for surface heterogeneity and the diversity of RP columns or provide accurate elution orders when the difference in the hydrophobicity between two compounds was small. This system was also described by Csokan et al. (B57). Galushko et al. also employed commercial analyte (structure)sensitive software to predict the appropriate initial binary mobilephase composition for RPLC; the effects of the concentration of an organic solvent in water on retention and chromatograms of compound mixtures were simulated (B58). Chemometric Approaches. Martinez-Vidal et al. developed a new automated sequential optimization method, optimization procedure by search point (OPSP), for the isocratic mobile-phase optimization for the separation of six selected pesticides. Eleven experiments were required to find the optimum using the OPSP method, compared to 15 and 36 experiments needed for the modified simplex and grid search procedures, respectively (B59). Gorburu et al. used artificial neural networks to optimize HPLC mobile-phase parameters. When working with the minimum number of “neurons”, they obtained solutions identical to those provided with nonlinear regression models. When the network contained excessive neurons, nonlinear regression techniques were unstable, having high intraparameter correlations and showing matrix singularities (B60). Following a factorial design and subsequent experiments, Ong et al. developed quadratic retention models that, together with overlapping resolution maps (ORMs), permitted the retention and resolution of pharmaceuticals to be optimized as a function of pH and the percentage of organic modifier (B61). They also used ORMs to predict optimum ternary and quaternary mobile phases for the separation of pharmaceuticals (B62). De Beer et al. utilized a face-centered central composite design to optimize the separation of methyl and propyl p-hydroxybenzoate (MPHB, PPHB), phenylephrine hydrochloride, and chlorphenamine maleate (CPM) (B63). The four mobile-phase parameters optimized were pH and the concentrations of methanol (modifier), sodium dioctylsulfosuccinate (ion-pair reagent), and dimethyloctylamine (competitive base), using mathematical regression models of retention and subsequent response surface plots. Kaufmann et al. reported a rational method based on partial least-squares (PLS) regression models for the initial targeting of optimum solvents, using mobile-phase data from the literature or from scouting runs to perform the targeting, thereby drastically reducing the initial number of solvent variables that need to be explored (B64). PLS models were used to relate mobile-phase composition with physicochemical properties. Further optimization was performed using a highly reduced factorial design for the optimization of pH, temperature, flow rate, etc., and a subsequent factorial design to generate a PLS model for the prediction of optimal chromatographic conditions (B65).

Lan et al. used a mixed-level orthogonal array design to optimize the determination of polycyclic aromatic hydrocarbons (PAHs) (B66). Wan et al. compared the advantages and the disadvantages of three-level and two-level orthogonal array designs for the optimization of pesticide separations, using as variables buffer pH and the percentages of acetonitrile and methanol (B67). Chee et al. employed a mixed-level orthogonal array design (OAD) to optimize six parametersstype of C18 column, concentration of methanol and acetonitrile in the mobile phase, isocratic and gradient time periods, and flow ratesfor the determination of 11 priority substituted phenols (B68). Rozbeh and Hurtubise used a window diagram approach to optimize binary mobile-phase conditions, followed by a solubility parameter method to optimize a ternary mobile phase for the separation of four classes of metabolites of benzo[a]pyrene (tetrols, diones, dihydrodiols) and monohydroxylbenzo[a]pyrenes (B69). Using a factorial design, Andersson et al. evaluated the influence on efficiency (N) and retention (k) of the following variables: pH, column temperature, and the type and charge of five modifiers (three uncharged, two charged). The pH and nature of the modifier were important for retention, whereas the pH and column temperature were important for column efficiency (B70). Matsuda et al. used information theory to simultaneously optimize mobile-phase composition, column length, detection wavelength, and flow rate; this approach was applied for assays of multiingredient drug formulations (B71). Arnoldsson and Kaufmann develped a general method for the analysis of lipid classes from animal and vegetable samples (e.g, oat kernel, soybean, and bovine milk), using a Plackett-Burman design to optimize the mobile phase and a factorial design to optimize detection and quantitation (B72). Chiral Separations. Kirkland found that on tris-3,5-dimethylphenyl carbamate-derivatized cellulose and other cellulose-based HPLC columns, the enantioselectivity and resolution can be significantly increased, and often optimized, by modifying nonpolar normal-phase eluents with certain aprotic solvents (B73). This complements earlier findings by others on the dependence of enantioselectivity on temperature and the type and concentration of alcohol modifiers in normal-phase eluents. A simple, systematic scheme for optimizing the separation of enantiomeric drugs with Chiralcel OD columns was proposed. Haupt et al. employed a three-factor central composite face design (CCF) to optimize, via pH and the concentrations of Tween 20 (surfactant) and heptanoic acid, the micellar liquid (MLC) separation of the enantiomers of alprenolol, oxprenolol, trimipramine, and propranolol on a Chiral AGP column. The responses evaluated were resolution, capacity factor (k′) of the last eluted enantiomer, and P5/log tR; the results showed that pH was the most important variable, with the optimum between 5.5 and 6.5 (B74). Penn et al. developed general equations and data analysis methods to relate mobilities in CE or capacity factors in HPLC to equilibrium (association) constants and to maximize mobility or retention time differences as a function of chiral selector concentration (B75). Results with β-cyclodextrin as a mobile-phase additive or a chiral stationary phase in CE and HPLC were compared; it appears that a rational link between LC and CE is possible, which may allow logical separation strategies to be transferred between the two fields. Column Studies. Using window diagrams and chromatography response factors, Wenclawiak and Hees systematically evaluated Analytical Chemistry, Vol. 68, No. 12, June 15, 1996

519R

10 standard HPLC columns for the separation of 16 U.S. EPA PAHs by gradient HPLC with an acetonitrile/water mobile phase. The best results were compared to those obtained by SFC with an acetonitrile/CO2 mobile phase with the same column (B76). Vervoort et al. employed chemometric methods to select and reduce from 32 to 5 the number of test compounds used to estimate the suitability of different stationary phases for basic compounds and drugs (B77). Although the five compounds were selected solely on the basis of asymmetry data for six different LC columns, three column characteristics were employed in the subsequent evaluation of eight commercial columns at pH 3, 7, and 11: peak asymmetry, efficiency, and repeatability of the retention factor and plate number. At pH 3 good results were obtained with Supelcosil LC-ABZ and Zorbax Rx-C18 columns, whereas at pH 11 good results were obtained with a column containing zirconium oxide coated with polybutadiene (3MZ-18). Finally, Staahle et al. used PLS to combine quantitative information about seven nucleoside analogs and 28 combinations of columns and mobile phases into a regression model for the retention time that agreed to within 15% of experimental data (B78). Gradient Elution. Matyska and Kossowski (B79) and Hamoir et al. (B80) employed commercial simulation software (Drylab G) to optimize the gradient elution separation of some nitrosamines and multicomponent drug formulations, respectively. Using resolution as the criterion, Wang et al. optimized the conditions for gradient elution by employing a two-factor (initial solvent composition C and gradient time T) grid search based on a polynomial estimation from nine preliminary experiments (B81). Good agreement was obtained between predicted data and experimental results. Miscellaneous. Bowater and McWilliam described three exercises where computers are being used to help students learn about HPLC: a simulation of chromatographic resolution, a combined computer/chemistry laboratory HPLC experiment, and an optimization of HPLC separation parameters (B82). Klyushnichenko et al. used three-dimensional plots of selectivity and resolution as a function of pH and ionic strength to optimize the separation of recombinant insulin products by RPLC and RP-IPC. A mechanism for the separation of proteins with a mobile phase containing a high salt concentration and a pH near the isoelectric point of the analyte proteins was proposed (B83). Torres-Lapasio et al. described an interpretive strategy for the optimization of surfactant and alcohol concentration in MLC, testing three optimization criteria (positional resolution, valley-to-peak ratio, area overlap) in conjuction with the retention model 1/k′ ) Aµ + Bφ2 + Cφ + Dµφ + E. Retention data from several phenols, aromatic compounds, and catecholamines were used to evaluate the procedure (B84). Hatrik et al. utilized the general exponential function to model tailed peaks and a threshold criterion based on the calculation of the degree of overlap in the computer-based optimization of the binary eluent for the separation of selected phenylurea herbicides and some of their aniline degradation products (B85). Howard et al. obtained response surfaces with sulfur chemiluminescence detection (SCD) under various methanol/ water elution conditions. Calibration curve linearity and linear dynamic range, response factors, and detection limits varied with mobile-phase composition. The separation of thiocarbamates extracted from apples was presented (B86). Applications. Despite the unusual retention behavior exhibited by 1-naphthyl isocyanate derivatives of linear alcohol polyethoxy520R


lates (LAEs) on a C18 column, Lemr et al. succeeded in optimizing their separation by optimizing the proportion of acetonitrile and water in the mobile phase (B87). Lintschinger et al. optimized the pH, concentration of the ion-pairing reagent, and polarity of the mobile phase for two different ion-pairing reagents, tetrabutylammonium phosphate (TBA) and tetraethylammonium nitrate (TEA), in the simultaneous determination of Cr(III) and Cr(VI) with chromium-specific detection by flame atomic absorption spectrometry (FAAS) and inductively coupled plasma mass spectrometry (ICPMS). Best chromatographic conditions were obtained with a polymer-based reversed-phase column (Hamilton PRP1) and mobile phases containing either TBA (1 mmol/L) in methanol/water (60:40) or TEA (2 mmol/L) in water at a pH between 3 and 4 (B88). Chaminade et al. utilized a cubic spline interpolation algorithm to optimize the selectivity obtainable with isocratic ternary mobile phases for the separation of phenolic antioxidants (B89). By studying the effect of mobile phase composistion on six quantitative chromatographic parameters (k′, w, R, N, HETP), Castillo et al. were able to optimize the separation of 12 citrus flavanones and flavones (B90). Han-Xi et al. used a computer-assisted, seven-experiment mixture design and polynomial retention model to optimize the separation of four four pesticide enantiomers in normal-phase LC (B91). Pichini et al. employed solvent optimization software to develop and optimize an isocratic RPLC method for nicotine, five of its metabolites, and caffeine under isocratic conditions and a quaternary mobile phase (methanol/acetonitrile/THF/buffer, 2.3:4.3:0.3:93.1) (B92). From reproducibility and linearity data, Carratu et al. optimized the derivatization, separation, and detection of amino acids in parenteral solutions using 9-fluorenylmethyl chloroformate as the reagent for derivatization (B93). Using a C18 column, Vinas optimized an acetonitrile/water mobile phase for the simultaneous determination of several sulfonamides in different foods, such as honey, milk, and eggs (B94). Finally, by studying the influence of the type of stationary phase, pH, amine modifier, and organic modifier on resolution, Andrisano et al. optimized the separation of five licorice triterpenoidss18β-glycyrrhetic acid (β-GA), 18R-glycyrrhetic acid (R-GA), 24-hydroxy-18β-glycyrrhetic acid (24-OH-β-GA), R- and β-liquiritic acidson a C18 column with a buffered hydroorganic mobile phase (B95). DATA ANALYSIS Stationary Phase Classification. On the basis of the normal-phase retention characteristics of over 30 well-characterized probe solutes, Whitman et al. used chemometrics to characterize the similarities and differences between eight different “acid”- or “base”-washed microporous zirconia supports (C1). The apparent lack of chromatographic reproducibility previously observed under normal-phase conditions on zirconia appears to be due to a lack of attention to the details of the “acid” or “base” pretreatment. Using test mixtures recommended in the literature to probe the hydrophobicity, free silanol interactions, trace metal activity, and shape selectivity, Olsen and Sullivan measured the chromatographic properties of 17 commercial octadecylsilyl phases and used principal component analysis (PCA) and cluster analysis to identify column similarities and differences that would aid in column selection for method development, choice of an alternate column, and method ruggedness testing (C2). Columns that were grouped together gave similar results with mixtures of pharmaceutical compounds. Vervoort et al. employed chemo-

metric methods to select and reduce from 32 to 5 the number of test compounds used to estimate the suitability of stationary phases for basic compounds and drugs (C3). Although the five compounds were selected solely on the basis of asymmetry data for six different LC columns, three column characteristics were employed in the subsequent evaluation of eight commercial columns at pH 3, 7, and 11: peak asymmetry, efficiency, and repeatability of the retention factor and plate number. At pH 3 very good results were obtained with Supelcosil LC-ABZ and Zorbax Rx-C18 columns, whereas at pH 11 very good results were obtained with a column containing zirconium oxide coated with polybutadiene (3MZ-18). Forgacs compared various multivariate mathematical/statistical methods for the evaluation of the relation between retention and the physicochemical parameters of 17 monoamine oxidase inhibitory drugs on a β-cyclodextrin polymercoated silica column using an eluent of MeCN and 0.05 M K2HPO4 (C4). Although cluster analysis required markedly less computer time, PCA followed by two-dimensional nonlinear mapping or varimax rotation provided a better separation of variables. Using a set of 15 quinolone derivatives analyzed by nine chromatography systems, Rotar et al. compared two different decision making tools, information content and numerical taxonomy, for their ability to select the optimal set of rationally chosen HPLC systems (C5). Retention/Solute-Stationary Phase Interactions. Altomare et al. employed quantum-chemical calculations (MNDO), PLS analysis, and 3D comparative molecular field analysis (CoMFA) to investigate the interaction mechanism of a variety of racemic alkyl aryl sulfoxides with a π-acid HPLC stationary phase (C6). Haldna et al. used PCA and correspondence factor analysis (CFA) to describe the behavior of five carboxylate ions (formate, acetate, propionate, n-butanoate, n-pentanoate) in ion chromatography and the influence of the carbonate concentration of the eluents. With PCA, only one factor is necessary to model the retention times of each ion studied, while CFA offers an analysis of second-order effects and shows how the selectivities of the chromatography systems are modified with either the carbonate concentration or the concentration ratio of NaHCO3 and Na2CO3 (C7). Modeling/Peak Characterization/Smoothing. Olive and Grimalt evaluated several diverse chromatographic peak models [Gaussian, log-normal, γ, Weibull, Haarhoff and der Van Linde, Littlewood, exponentially modified Gaussian (EMG), GramCharlier, and Edgeworth-Cramer series] for their ability to describe peak profiles generated from different numerical solutions to the mass balance equation (C8). The profiles obtained depended on the assumptions made for the type of adsorption isotherm (linear, Langmuir, or Freundlich) and the sample injection profile (pulse, exponential, reverse ramp, semiparabolic, or triangular). The EMG function was shown to be a good model for the combination of a linear isotherm and symmmetric or exponential sample injection, whereas the Haarhoff and der Van Linde and log-normal functions were better with the Langmuir and Freundlich isotherms, respectively. Morton and Young tested the accuracy of the numerical integration methods for the measurement of statistical moments of chromatographic peak profiles, first with simulated EMG peaks (predetermined moments) and then with gas/liquid chromatographic data (C9). Cataldi and Rotunno showed how the Kalman filter can be used

to optimize cubic spline functions for the digital smoothing of both synthetic and experimental data (C10). Calibration and Curve Fitting. Hayashi et al. described a new way to measure the limit of detection (LOD), where the power spectral density of instrumental baseline variation is fitted by the simplex least-squares methods with a mixed random process of white noise and Markov process as a model (C11). Szabo et al. computed standard curves and validation points for the HPLC determination of four drugs (carbamazepine and phenytoin at therapeutic drug monitoring concentrations and deuterium-labeled carbamazepine and phenytoin at tracer dose concns.) using standard least-squares linear regression analysis and six alternative regression techniques (weighted 1/x, 1/y, 1/x2, 1/y2 least-squares linear, log/log least-squares linear, and robust). The coefficient of determination (R2) and the coefficient of prediction (R2pred) values for standard curves and the computed values for validation points did not differ significantly among the seven methods. The limit of quantitation (LOQ) values obtained with all six of the alternative regression methods were significantly lower (P < 0.01) than the LOQ values obtained with least-squares linear regression analysis (C12). Walsh and Diamond discussed the advantages of Microsoft Excel Solver for teaching nonlinear curve fitting (C13). Complete control of the modeling process lies with the user, who must present the raw data and enter the equation of the model, in contrast to many commercial packages bundled with instruments which perform these operations with a “black box” approach. Deconvolution. Yamamoto et al. proposed the use of a derivative spectrum chromatogram for the deconvolution of overlapped peaks in real time and described the performance of this approach with real data obtained during the separation of pesticides by HPLC (C14). On simulated two- and three-analyte systems, Toft and Kvalheim evaluated the performance of the three curve resolution techniquessalternating regression (AR), iterative target transformation factor analysis (ITTFA), and heuristic evolving latent projections (HELP)sin multicomponent chromatography (C15). Song et al. used target transformation factor analysis (TTFA) on raw retention time/absorbance data to resolve the overlapping peaks of dysprosium and yttrium (C16). Factor Analysis. Brereton et al. described five studies in which evolutionary factor analysis (EFA), also known as window factor analysis, was applied to multichannel (diode array) HPLC data: (i) a method for selecting and ranking variables that provide the best resolvability in the nonsequential direction of a two-way data matrix (e.g., wavelength in diode-array HPLC) (C17); (ii) a comparison of three methods for determining eigenvalues (meancentered sequential scores, mean-centered sequential loadings, and uncentered data simulations and real data of two-way data matrixes) (C18); (iii) a comparison of three indexes of the quality of data reconstruction (C19); (iv) an approach to multipeak clusters based on “resolvability indexes” and variable selection in factor analysis (C20); and (v) the influence of noise, peak position, spectral similarities, and relative peak intensities on the resolvability of HPLC diode-array data (C21). Miscellaneous Fundamental Studies. For purposes of pattern recognition based on PCA, Malmquist and Danielsson developed a procedure to align a sample chromatogram with a target chromatogram by compensating for (i) small shifts in retention time (not due to different sample components), (ii) common variations in peak area (not due to sample composition), Analytical Chemistry, Vol. 68, No. 12, June 15, 1996

521R

and (iii) variations in level and slope of the baseline. After utilizing the EMG model in their simulations, they demonstrated the effects of the alignment procedure on the PCA on a set of chromatography profiles intended for peptide mapping (C22). Round et al. developed a peak-tracking algorithm based on a normalized spectral comparison of any two chromatographic peaks (overlay method) in the separation of amino acids, peptides, and proteins. The spectrum of each peak in the first chromatogram is compared with the spectra of every peak in the second chromatogram to determine the best cross-match (C23). Johnston used EMG functions to simulate HPLC fluorescence signals and showed that electronic baseline offset errors of NaBr > ) NaNO3 > Na2SO4 (I95). Bieganowska and Petruczynik studied the combined effects of organic modifier and ion-pair reagent concentration (alkylammonium salts and bis(2-ethylhexyl)orthophosphoric acid) on the retention of some isomeric 2-benzoylbenzoic acids (I96); the effects of the individual substituents on retention were quantified by ∆ log k′ and ∆RM values. Shamsi and Danielson compared the separations of long-chain aliphatic anionic surfactants (alkyl SO4- and alkane SO3-) on three mixed-mode stationary phases Analytical Chemistry, Vol. 68, No. 12, June 15, 1996

541R

(RP C8/-, RP C4/-, and RP phenyl/-anion exchange) using a naphthalenedisulfonate (NDS)/acetonitrile mobile phase. The RP phenyl/-anion exchange column, using 0.2 mM NDS with ∼90% ACN, was the best combination for the separation of the C6-C18SO4- or C6-C18SO3- mixtures in ∼30 min (I97). pH Effects. Meynial et al. used tetrabutylammonium hydrogen sulfate (TBAHS) as an ion-pair reagent to simultaneously separate nucleotides and nucleotide sugars (I98). Using a linear elution gradient, they studied the influence on solute retention of the counterion concentration, the mobile-phase pH, and the temperature to locate the optimum conditions: 2.5 mM TBAHS in a pH 6.9 potassium phosphate buffer at ambient temperature. UDPgalactose, NADH, NAD+, and UTP were quantitatively determined during lactose synthesis by a galactosyltransferase (EC 2.4.1.22). Larew et al. studied the retention and resolution of olanzapine and desmethylolanzapine as a function of the percentage of acetonitrile, the ion-pairing reagent concentration, and the buffer pH and then compared the theory-based software package DryLab I/mp with empirical equations derived by the authors to predict the dependence of the chromatography behavior on each of the experimental variables. The empirical equations derived from the statistical analysis were found to predict better the chromatography behavior over the ranges tested, especially at the lowest ionpairing reagent concentration, where the accuracy of DryLab I/mp was the poorest (I99). After systematically evaluating the influence of mobile-phase pH, type and concentration of the organic modifier, concentration of the ion-pairing agent, and the buffer, Thoithi separated diamino analogs of 2′- or 3′-deoxyadenosine from adenine on a poly(styrene-divinylbenzene) polymer column using a mobile phase consisting of THF/0.2 M sodium octanesulfonate/ 0.2 M potassium phosphate buffer (pH 2.0)/water (15:25:30:30) (I100). Torniainen and Maeki developed an RP-IPC method for monitoring the photodegradation of ciprofloxacin (I101). During their study they investigated changes in the chromatographic behavior of ciprofloxacin and its degradation products as a function of organic modifiers, anionic and cationic ion-pair reagents, and pH; baseline separation was achieved with an eluent of acetonitrile/phosphoric acid (20 mM, pH 2.3) containing 2.5 mM sodium heptanesulfonate. Similarly, Botsoglou et al. studied the chromatographic behavior of the anthelmintic fenbendazole and its major metabolite oxfendazole, including the effect of adding negatively and/or positively charged ion-pair reagents, mobilephase pH and composition, and column temperature (I102). Barany et al. measured the adsorption of three zwitterionic ionpairing agentss11-aminoundecanoic acid, 8-aminooctanoic acid, and 6-aminohexanoic acidson a C18 column as a function of pH (3-8) and observed a maximum near the isoelectric point. Subsequent separations of fluoroquinolone gyrase inhibitor derivatives were also pH dependent (I103). Contreras-Martinez and Vera-Avila determined the effects of mobile-phase composition on retention and selectivity of thyrotropin-releasing hormone (TRH) and some metabolites [deamido-TRH (TRHOH), histidylprolinediketopiperazine, proline and prolineamide] (I104). Small modifications of the pH (near pH 2) greatly enhanced the separation of TRH and its analog TRHOH, and remarkable improvements in peak width and peak shape were observed for some analytes when a potassium salt was added to the mobile phase. Giroux and Barkley separated Cu(I), Ag(I), Ni(II), Au(I), Co(III), Fe(III), and Fe(II) cyano complexes on silica- and carbonbased reversed-phase stationary phases. The separarations were 542R


affected by a number of experimental factors including the pH, the nature and concentration of the organic modifier and the ionpair reagent, and the ionic strength of the mobile phase. Differences in the elution order of metallocyanides in this work vs other investigations under similar conditions were explained by differences in ionic strength (I105). Chandler et al. described the influence of solvent pH, alcohol, acid, and ion-pairing agent on the separation and quantitation in biological samples of chlorambucil N-oxide and chlorambucil (I106). Nesterenko and Ivanov used a polyampholyte eluent to generate an isoconductive pH gradient for the separation of transition metals on a column packed with tetraethylenepentamine-bonded silica and detection by conductivity (I107). Bare Silica. Juskowiak used a binaphthyl-containing cationic surfactant to modify bare silica to achieve a reversed-phase-type separation of aromatic compounds (I108). Hydrophobic and ionpairing interactions were dominant for the nonionic and anionic compounds, respectively. Simmons and Stewart separated selected cardiovascular agents (propranolol, atenolol, metoprolol, verapamil, diltiazem, nifedipine, clonidine, prazosin) on underivatized silica with an eluent of acetonitrile/aqueous phosphate buffer (best conditions were 2:3 acetonitrile/pH 3 phosphate) (I109). Ion pairing appeared to be the primary interactive force between the silica column and the analytes, but evidence for hydrogenbonding and hydrophobic interactions was also observed. Increased retention and lower efficiencies were observed with methanol. Inorganic Analytes. Hu and Haraguchi reported a direct determination of sodium, potassium, magnesium, and calcium ions in human saliva by ion chromatography using a taurine-conjugated bile salt micelle-coated stationary phase. The sulfonate charges acted as the ion-exchange sites for the separation of cations, while the cavity of the helical micelle acted as a size-exclusion site for the rapid elution of large organic compounds (I110). Ohtsuka et al. compared the retention and resolution of Cu(II), Co(III), Ni(II), and Fe(II) chelates with 2-(5-bromo-2-pyridylazo)-5-[Npropyl-N-(3-sulfopropyl)amino]phenol (5-Br-PAPS) and 2-(5-nitro2-pyridylazo)-5-[N-propyl-N-(3-sulfopropyl)amino]phenol (nitroPAPS) as a function of mobile-phase composition in methanol/ water and acetonitrile/water mobile phases with 0.05 M sodium ion and 0.02 M Tris buffer (pH 7). The acetonitrile/water mobile phase provided baseline resolution for all chelates (I111). Applications. Johnston et al. compared RPLC and RP-IPC for the determination of strychnine in animal tissues and obtained better results with RPLC (I112). Proksch et al. separated anthrapyrazole CI-941 and its metabolites in serum and urine on a C18 column with a mobile phase of acetonitrile/water (19:81 v/v) containing 5 mM 1-pentanesulfonic acid and achieved a detection limit of 5 ng/mL at a wavelength of 491 nm (I113). Wedge et al. determined the novel antifolate anticancer drug (6R)5,10-dideaza-5,6,7,8-tetrahydrofolate (lometrexol) in human plasma and urine by RPLC and RP-IPC with LOQs of 200 and 10 ng/mL, respectively, using absorbance and fluorescence detection (I114). Rivory and Robert described a sensitive and selective HPLC method for the simultaneous quantitation in plasma of the carboxylate and lactone forms of the camptothecin derivative irinotecan CPT-11 and its metabolite SN-38; the mobile phase was 0.075 M ammonium acetate buffer (pH 6.4)/acetonitrile (78:22 v/v), with 5 mM tetrabutylammonium phosphate (I115). Saini et al. developed a method for the RP-IPC determination of sodium

mercaptoundecahydrododecaborate (BSH) in rat tissues using a C18 column and an optimized mobile phase of methanol/0.02 M (pH 7.0) phosphate buffer (43:57 v/v) with 0.010 M tetrabutylammonium dihydrogen phosphate (I116). Ameno et al. determined diquat (DQ) and its two metabolites (DQ-monopyridone and -dipyridone) in rat serum and urine by RP-IPC (I117). Koelbl et al. studied tetraalkylammonium salts as ion-pairing reagents for the RP-IPC separation of selenite and selenate (I118); absolute detection limits were 31 and 51 ng of Se for selenite and selenate, respectively (100-µL injection). Zhang et al. separated and determined platinum(II) in cisplatin and carboplatinum samples using 4,4′-bis(dimethylamino)thiobenzophenone (TMK) as a precolumn complexing agent and spectrophotometric detection at 520 nm (I119). Hasinoff et al. separated the terbium(III)ADR-925 complex on a C18 column with an isocratic eluent of 50% methanol and 50% 4 mM 1-heptanesulfonate and achieved a detection limit of 25 pmol using fluorescence detection (I120). Walsh et al. resolved 7-ethoxycoumarin, 7-hydroxycoumarin, and their glucuronide and sulfate conjugates by RP-IPC (I121). Resmini and co-workers identified and quantified glucosylisomaltol 2-acetyl-3-D-glucopyranosylfuran (AGPF) in pasta dried under different conditions (I122). Abidi et al. separated phosphatidylethanolamine (PE) derivatized with fluorescein-, thiocarbamoyl-, pyrenesulfonyl-, and (dimethylamino)naphthalenesulfonyl (dansyl) fluorophores on octadecylsilica with a mobile phase of acetonitrile/ methanol/water in the presence of tetraalkylammonium phosphates (TAAPs); dansylated phosphatidylserines and PE plasmalogens (ether-linked phospholipids) were also resolved under similar conditions (I123). Murray and co-workers reported a general procedure for the purification of chemically synthesized oligoribonucleotides (1048 nucleotides) (I124). Misra et al. separated by RP-IPC or by immunoaffinity chromatography 1,N6-etheno-2′-deoxyadenosine and 3,N4-etheno-2′-deoxycytidine in cellular DNA after enzymatic digestions of the latter (I125). Lazzarino et al. compared the levels of myocardial malondialdehyde (MDA), oxypurines, and nucleosides in the coronary sinus and aortic root by RP-IPC (I126). Bernocchi et al. determined creatine phosphate, purine, and pyridine nucleotides in cardiac tissue using a C18 column and an aqueous eluent containing phosphate buffer (pH 7.8) and tetrabutylammonium ion (I127). Schobert purified the ATP analogs such as tubercidin 5′-triphosphate, formycin A 5′-triphosphate, and etheno-ATP, from their respective mono- and diphosphate using a C18 column and a volatile mobile phase (pH 7) containing tributylamine (I128). Bedford et al. obtained a good separation (and determination) of uridine 5′-diphospho-R-D-glucuronic acid and its hydrolysis products using a 1:1 mixture of the ion-pair reagents tetrabutylammonium hydroxide and tetraethylammonium hydroxide (I129). Brueggemann et al. utilized a perfusion-type reversed-phase column in the ion-pairing mode to separate 5′,5′dinucleotides within 10 min with high reproducibility, resolution, and capacity (I130). Sypniewski and Bald converted cysteine, glutathione, homocysteine, acetylcysteine, N-(2-mercaptopropionyl)glycine, and its metabolite 2-mercaptopropionic acid into their S-pyridinium derivatives with 2-chloro-1-methylpyridinium iodide and then separated them isocratically with 0.175 M citrate buffer containing 0.010 M sodium octanesulfonate (pH 2.8)/acetonitrile/methanol (82:6:12) as the optimum mobile phase (I131). Voelker et al. achieved a baseline separation of the octapeptide angiotensin II

and related peptides using an isocratic eluent of acetonitrile and heptafluorobutyric acid at 38 °C (I132). Chang and Wang reported a sensitive method for determining nefopam in plasma on a Nova-Pak C18 column and a mobile phase of ACN, 0.05 M phosphate buffer (pH 3.0), and sodium propanesulfonate (I133); the detection limit using fluorescence was 0.5 ng, and recoveries after sample preparation were 94%. Valladao and Sandine separated the C12, C14, and C16 components of n-alkyl(dimethylbenzyl)ammonium chloride from an extract of milk by RP-IPC (I134). Garcia-Sanchez et al. separated in less than 20 min the pesticides asulam, propoxur, coumatetralyl, biphenyl-2-ol, and thiabendazole using a complex hydroorganic mobile phase containing methanol, acetic acid, sodium cholate, tetramethylammonium hydrogen sulfate, and triethylamine. Recoveries from spiked apples and wheat grains ranged from 94 to 105% with RSDs between 1.4 and 9.2% and detection limits between 0.1 and 1.9 ng (I135). Spoehrer and Eyer separated the syn-syn, syn-anti, and anti-anti geometrical isomers of obidoxime (I136). Ramsauer et al. developed a method for the determination of 1-β-D-arabinofuranosylcytosine-5′-stearyl phosphate (cytarabine-ocfosfate) using a phenyl-bonded column with a mobile phase of acetonitrile-buffered water (pH 6.8) (50: 50) (I137). Akins and Kumar employed serial CN and C18 stationary phases with an eluent containing lithium perchlorate for the separation of a mixture of cyanine dyes (I138). Using 100 mM triethylammonium acetate as ion-pairing reagent, Oefner et al. separated phosphodiester oligonucleotides labeled fluorescently at their 5′-terminus on alkylated nonporous 2.3-µm poly(styrene-divinylbenzene) particles. Since the technique allows the separation of PCR products differing only 4-8 base pairs in length within a size range of 50-200 base pairs, it may be employed for the quantitative assessment of competitive PCR (I139). OPTICAL AND POSITIONAL ISOMERS The volume of literature emerging on optical and positional isomer separation has continued to rise sharply this period. Our literature search turned up over 600 original papers. Many of these were specific applications and will not be discussed here. However, numerous review articles were published which will alert the reader to many of the articles that we were forced to exclude. REVIEWS During this period, a special volume of Journal of Chromatography was dedicated to recent advances in the most successful stereoselective separation methods. Each topic area was introduced by a review article. Welch presented a thorough historical review of the design of chiral stationary phases (CSPs) for HPLC in the Pirkle laboratories (J1). Beginning with the early CSPs developed following the discovery, more than 25 years ago, of the nonequivalence of NMR signals arising from enantiomers in the presence of chiral solvating agents, he described the rationale behind the development of many phases including the most recent families of chiral selectors. Allenmark and Andersson reviewed the recent progress made in the application of amino acid-derived chiral selectors (J2), while Wainer gave an overview of the use of CSPs, particularly protein or enzyme CSPs, as probes for ligand/ biopolymer interactions (J3). Okamoto and Kaida reviewed chiral resolution by HPLC using polysaccharide carbamates and benzoates as CSPs (J4), and Davankov presented a review discussing Analytical Chemistry, Vol. 68, No. 12, June 15, 1996

543R

theoretically expected general correlations between retention, enantioselectivity, and efficiency in ligand-exchange chromatography (LEC) (J5). In addition, theoretical studies of brush-type CSPs (J6) and the contribution of preparative chiral chromatography (J7) were addressed by Lipkowitz and by Francotte, respectively. Many other reviews, some covering the topic areas already mentioned, have also been published this period. From the pharmaceutical viewpoint, Camilleri et al. reviewed the various HPLC methods available for resolving racemic mixtures (J8). Cleveland explored and discussed the enantioselectivity of various Pirkle-concept CSPs for the direct HPLC separation of drugs belonging to six major pharmaceutical classes (J9). Pirkle and Welch reviewed the separation of compounds on recently developed HPLC CSPs which use simultaneous face-to-face and faceto-edge π-π interactions to facilitate chiral recognition (J10). Isaksson et al. investigated the use of cellulases, especially for the separation of chiral basic drugs in both liquid chromatography and electrophoresis (J11). Oguni et al. reviewed the development of CSPs prepared from polysaccharide derivatives and discussed the importance of conformational rigidity in order to obtain good chiral recognition ability (J12). Maccarrone reviewed chiral recognition by functionalized cyclodextrin-metal complexes (J13). Issaq compared chiral separations in CE with HPLC and GC and discussed the advantages of each technique (J14). Zhou et al. summarized recent research on derivatization methods used for the separation of enantiomeric alcohols (J15), and Gergely briefly reviewed the applications of circular dichroism as a detector in both preparative and analytical liquid chromatography (J16). Several reviews were presented concerning the separation of specific chiral compound types. Lough and Noctor reviewed multicolumn approaches to chiral bioanalysis by LC (J17). Massey and Tandy, drawing on experiences gained from chiral HPLC method development within Zeneca Agrochemicals, discussed the challenges and frustrations in the separation and analysis of chiral agrochemicals (J18). Tokuma and Noguchi reviewed the stereospecific assay methods for dihydropyridine calcium antagonists in plasma or serum with emphasis on the use of CSPs in HPLC (J19). Ruiz-Gutierrez and Barron discussed the most commonly employed methods in the analysis of triacylglycerols in natural fats and considered the main advantages and disadvantages of each (J20). Finally, Krueger surveyed methods employed in the detection of synthetic and artificial flavors (J21). New Chiral Stationary Phases. The number of new CSPs introduced since the last review period has increased significantly. Some new CSPs do show chiral selectivity toward a range of compounds; however, many are tailor-made CSPs, developed for specific compound types due to a much greater understanding of chiral interaction mechanisms. In addition, several new versions of “old” CSPs were introduced following new developments in methods of immobilization. Hyun and co-workers reported several new brush-type CSPs for LC in this period. Two were CSPs bearing both π-acidic and π-basic sites, prepared from (S)-tyrosine (J22) and from (S)naproxen and 3,5-dimethylaniline (J23). Both CSPs were shown to be useful in resolving a variety of either π-basic or π-acidic racemates. Another CSP was prepared from (R)- or (S)-Rnaphthylethylamine and (S)-naproxen and thus contained two chiral centers (J24). The CSP prepared from (R)-R-naphthylethylamine and (S)-naproxen was found to be very successful in 544R


resolving 3,5-dinitroanilide derivatives of antiinflammatory drugs related to R-arylpropionic acids. Pirkle and co-workers also described several new CSPs for LC this period. In one, (S)-naproxen was hydrosilylated with either dimethylchlorosilane, which led to a brush-type phase or with polymethylhydrosiloxane, which led to a polymeric CSP (J25). The polysiloxane-based CSP was found to exhibit higher enantioselectivities and short retention times for some nonsteroidal antiinflammatory drugs (NSAIDS) than did its brush-type counterpart. In another report, a series of polysiloxane-based CSPs derived from (S)-naproxen diallylamide, using either a segmented or pendent chain polymer formation was described (J26). These polysiloxane-based CSPs were shown to have reduced retention and comparable or higher enantioselectivity than the corresponding brush-type CSP. Concerned also with the design and optimization of brush-type CSPs, Pirkle and Bowen showed how stepwise modification of a π-basic CSP derived from (S)-N-(1naphthyl)leucine undecenyl ester could lead to new CSPs with enhanced enantioselectivity toward several test analytes (J27). Veigl et al. synthesized a new CSP based on immobilized (S)N-(3,5-dinitrobenzoyl)tyrosine methyl ester and demonstrated the separation of a broad range of chiral compounds (J28). Maher et al. prepared a new family of CSPs by the chemical modification of ring-opened D-δ-gluconolactone (J29). The CSPs derived from the ring-opened gluconolactone in which the hydroxyl groups had been converted to carbamate residues using a naphthylethyl isocyanate were shown to have the highest enantioselectivity toward the test racemates. Lohmann and Dappen prepared novel (R)- and (S)-β-lactone CSPs and noted that their easy and economic preparation would make them useful for both analytical and preparative applications (J30). Lin and Lin prepared a CSP from alanyl- and pyrrolidinyl- disubstituted cyanuric chloride for the enantioseparation of methyl esters of N-(3,5-dinitrobenzoyl) amino acids (J31). (Chloromethyl)phenyl carbamate derivatives of cellulose (J32) and amylose (J33) coated onto silica gel were prepared by Chankvetadze et al. The elution order and enantioselectivity were found to be greatly dependent on the positions of the substituents. In an attempt to alleviate the incompatibility of some HPLC solvents with coated derivatized polysaccharide CSPs, Yashima et al. regioselectively bonded 3,5-dimethylphenyl carbamates of cellulose and amylose to silica gel (J34). The enantioselectivities of the CSPs were found to depend not only on the position of immobilization but also on the amount of diisocyanate used for the immobilization. In a different approach, Oliveros et al. prepared a cellulose derivative bearing both a (3,5-dimethylphenyl)amino carbonyl and a 10-undecenoyl group and added a crosslinking agent in the presence of different types of solid supports including silica gels, graphite, and alumina (J35). Bonded CSPs prepared using this novel method were found to be compatible with many HPLC solvents and showed selectivity toward several chiral drugs. Stalcup and Williams showed that 1-(1-naphthyl)ethyl carbamate derivatives of maltooligosaccharides bonded to silica could be used for the separation of 3,5-dinitrobenzoylderivatized amines and amino acids as well as some 3,5-dinitrophenyl carbamoylated alcohols (J36). Perhaps one of the most interesting new class of chiral selectors introduced this period was the macrocyclic antibiotics, developed by Armstrong et al. (J37). These large chiral selectors were covalently bonded to silica gel, and the separation of over

70 structurally different chiral compounds was demonstrated. The CSPs were also shown to be multimodal in that they can be used in both the normal-phase and reversed-phase modes without any irreversible changes to the enantioselectivity. Several protein- and biomolecule-based stationary phases were also introduced. Hermansson and Grahn investigated the basicity of a new chiral column based on silica-immobilized cellobiohydrolase I (CBH I) using 32 different drugs and endogenous compounds (J38). In a similar study, Henriksson et al. immobilized intact and fragmented cellobiohydrolase II (CBH II) CSPs (J39). Both acidic and basic chiral compounds could be resolved, although their selectivities were found to be quite different from CBH I. Aubry et al. prepared a new CSP based on mixed immobilized HSA and an R1-acid glycoprotein (AGP) and were able to show that this new mixed CSP had a wider range of applications than the individual HSA or AGP CSPs (J40). Gasparrini et al. prepared a new CSP by covalently attaching a synthetic C3 symmetry, O-allyl-protected tyrosyl macrocycle to γ-mercaptopropyl silica gel and obtained extremely high separation factors for Boc-protected amino acid derivatives (J41). Massolini et al. immobilized hen egg yolk riboflavin protein on silica gel for the separation of chiral drug enantiomers in the reversed-phase mode (J42) and Sinibaldi et al. bonded an aminopropyl derivative of the ergot alkaloid (+)-terguride to silica and demonstrated the resolution of dicarboxylic acids, 2-arylcarboxylic acids, and amino acid derivatives (J43). Several new polymer CSPs have emerged this period. Hosoya et al. described a one-pot method for the preparation of a uniformsized polymer-based CSP for HPLC using poly(methylacrylamide) as the chiral selector (J44). Schleimer et al. synthesized two polysiloxane-based CSPs derived from a π-acidic N-(3,5-dinitrobenzoyl)-β-amino acid (JEM-1) and a π-basic N-(1-naphthyl)leucine selector (J45). High enantioselectivity was observed under both normal- and reversed-phase conditions. Terfloth et al. incorporated a brush-type chiral selector into polysiloxane-based CSP for use in HPLC and SFC (J46). Yashima et al. synthesized a stereoregular poly(phenylacetylene) bearing (R)-phenylethylcarbamoyl groups (J47), and Kobayashi et al. prepared a CSP composed of optically active polyurethanes (J48). Interest has also continued in the development of novel molecularly imprinted polymers for chiral recognition, despite the fact that the imprinting and, hence, enantioselectivity are not always permanent (J49). Ramstroem et al. studied a polymer prepared against Ac-L-Phe-L-Trp-OMe and evaluated nonionic and noncovalent interaction-based recognition (J50). Welch developed an imprintable brush-type CSP using enantiopure naphthamide as the imprint molecule (J49). Kempe and Mosbach reported on two novel molecularly imprinted stationary phases for the separation of amino acids, peptides, and proteins (J51, J52). High racemic resolution and high loading capacity were demonstrated for both CSPs. Keuster and Dosenbach synthesized a novel CSP derived from the atropisomeric enantiomer (S)-3,3′-dicarboxy-2,2′-dihydroxy-1,1′binaphthyl (S-DDBN) for the separation of a pharmaceutically interesting class of benzergoline derivatives (J53). Tichy et al. developed a new axially chiral phase with C2 symmetry from (R)(+)-6,6′-dinitrobiphenyl-2,2′-dicarboxylic acid, ionically bonded to silanized silica for the separation of vicinal benzamido alcohols (J54). Uray et al. synthesized and evaluated four diastereomeric CSPs based on mono-3,5-dinitrobenzoylated 1,2-diphenylethane-

1,2-diamine (DPEDA) as chiral selectors in normal-phase HPLC (J55). Finally, Knox and Wan reported on a new type of CSP prepared by coating porous graphite with a near-monolayer of an enantiomeric modifier such as L- or D-N-(2-naphthalenesulfonyl) phenylalanine (J56). Using complexation with cupric ions, baseline resolution of R-amino and R-hydroxy acids were achieved. A few papers describing new bonding methods for previously developed CSPs have emerged this review period. Both Pirkle et al. and Hyun et al. have proposed improved methods for the preparation of (S)-naproxen CSPs. Pirkle et al. linked (S)naproxen to silica through a silane tether containing a secondary amine group instead of the usual primary amine group (J57). This avoided the presence of a secondary amine group which often serves to increase retention and reduce resolution. Hyun et al. immobilized the 3,5-dimethyldianilide derivative of (S)-naproxen on silica gel through the 6-methoxy-2-naphthyl functionality of (S)naproxen (J58). Both new methods of immobilization were claimed to provide a CSP with superior performance compared to CSPs prepared by the previous methods. Lin and Yang studied the role of the π-π interaction provided by the benzyl group of N-benzylcarbamoyl-derived CSPs and found that this group was a significant source of nonstereoselective interactions. Therefore in order to reduce this undesirable effect, they prepared several N-alkylcarbamoyl derivatives of (S)-phenylglycine or (S)-phenylalanine and were able to demonstrate improved chiral discrimination (J59). Finally, Pirkle and Selin prepared an improved version of the 2,2,2-trifluoro-1-(9-anthryl)ethanol CSP (J60). They tethered the chiral selector to silica using an 11-carbon-atom chain at the 10-position of the anthryl ring and found that the CSP had greater enantioselectivity than its predecessor. Liquid-Phase Additives/Derivatization. In HPLC, Bazylak separated a set of underivatized chiral primary and secondary amino alcohols using a novel neutral, square planar, helically distorted nickel(II) chelate (J61). Roussel and Favrou separated a series of phenylhydantoin and methylhydantoin derivatives of amino acids using a new cationic β-CD derivative (J62). Using a porous graphitic carbon stationary phase, Josefsson et al. separated two racemic dihydropyridines and a proprietary racemate with chiral ion-pairing reagents [(1S)-(+)-10-camphorsulfonic acid or (1S)-(+)-3-bromo-10-camphorsulfonic acid] dissolved in dichloromethane/methanol (v/v 25:75); when acetonitrile substituted for methanol, no enantiomer separation could be obtained (J63). Using a similar stationary phase, Huynh et al. used the chiral ionpairing reagent N-(benzyloxycarbonyl)glycyl-L-proline in a methanolic mobile phase to separate several amines of pharmacological interest (alprenolol, sotalol, terbutaline, promethazine, trimipramine) (J64). Several new derivatizing agents were introduced this period. Pawlowska et al. used aromatic anhydrides as achiral derivatizing agents for the separation of aliphatic and aromatic amines (J65). Iwaki et al. developed chiral derivatization reagents possessing a dansyl (N-dimethylaminonaphthalene-5-sulfonyl) moiety for the separation and sensitive detection of carboxylic acid enantiomers (J66). Kondo et al. introduced 6-methoxy-2-(4-substituted phenyl)benzoxazoles for the separation of carboxylic acid enantiomers (J67) and N-[4-(6-methoxy-2-benzoxazolyl)]benzoyl-L-amino acids as chiral derivatizing reagents for amine enantiomers (J68). Nishida et al. synthesized carboxylic acids with a benzodioxole skeleton for the separation of amino acids (J69). Finally, Toyo’oka and Liu developed 4-[2-(chloroformyl)pyrrolindin-1-yl]-7-nitro-2,1,3Analytical Chemistry, Vol. 68, No. 12, June 15, 1996

545R

benzoxadiazole [(R)-(+)-NBD-Pro-COCl and (S)-(-)-NBD-ProCOCl] for the separation of chiral amines and alcohols (J70) and optically active Edman-type reagents for the separation of amino acids and other chiral compounds (J71, J72). Theory/Mechanism/Method Development. Penn et al. presented a systematic approach for the treatment of enantiomeric separations in CE and LC using chiral mobile-phase additives (J73). General equations and data analysis methods were given to relate mobilities or capacity factors to equilibrium constants in binding equilibria and to maximize mobility or retention time differences as a function of selector concentration. Stringham et al. described the use of subcritical fluid chromatography for the separation of several chiral intermediates (J74). They noted that there were pronounced advantages in the speed and ease of method development compared to HPLC. Tran et al. developed a novel chiral detector for HPLC based on the measurement of vibrational circular dichroism (J75). Advantages of this new detector included a much higher sensitivity compared to previous circular dichroism detectors and the ability to virtually detect any chiral compound that has an OH group. The mechanisms of interaction for brush-type CSPs are frequently predictable and are often discussed following the preparation of a new CSP. However, for multiple interaction phases, such as protein or polysaccharide CSPs, the mechanisms of interaction are less well understood and a few publications this period have addressed this issue. Haginaka et al. isolated fractions of chicken ovomucoid (J76) and BSA (J77), and Pinkerton et al. isolated fractions of turkey ovomucoid (J78) in order to determine which fractions contained chiral recognition ability. Allenmark attempted to gain further insight into the mechanism by which BSA discriminates between organic acids by using radioisotopically labeled samples (J79) and Loun and Hage characterized the thermodynamic processes involved in the binding and separation of (R)- and (S)-warfarin on a HSA column by using frontal analysis (J80). Yashima et al. have investigated the binding of transstilbene oxide to cellulose derivatives using NMR (J81) and computational studies (J82). Both methods predicted that the most important adsorbing site for trans-stilbene oxide was the NH proton of the carbamate residue. The computational method went a step further and suggested that it was the NH protons at the 3-position of the glucose unit that were most important. Burger et al. used free energy perturbation (FEP) calculations to reproduce experimentally determined binding enantioselectivities on podand ionophores to within 300 cal/mol (J83). Finally, Durham and Liang modeled and energetically optimized the complexes of β-cyclodextrin with R and S enantiomers of methylphenobarbitone; their results suggested that the favored conformation is distorted from a symmetric torus, with the guest molecules adopting an orientation in which the phenyl-ring is projected into the torus cavity (J84). Several researchers examined the effect of mobile-phase composition and other experimental variables for cellulose-, Pirkle-, and protein-based chiral columns. About a third of these studies compared the results obtained in very different separation modes. Dyas et al. examined the influence of the alcohol modifier on the enantioselective separation of nadolol, separating the isomers as their chiral 1-naphthylureides on a column consisting of 3,5-dinitrobenzoyl-L-leucine covalently bound to 3-µm (aminopropyl)silica, using a mobile phase of n-hexane and alcohol; the best separation was achieved with ethanol as the modifier (J85). 546R


Furuta and Doi compared the retention and enantiomeric separation of a thiazole derivative and related compounds by HPLC using a β-CD bonded stationary phase and MEKC with β- or γ-CD as a chiral additive (J86). Kirkland reported that enantioselectivity and resolution on cellulose-based HPLC columns can be significantly increased, and often optimized, by modifying the nonpolar mobile phase with certain aprotic solvents; based on these results, a simple, systematic scheme was proposed for optimizing the separation of enantiomeric drugs with Chiralcel OD columns (J87). McCarthy developed both a normal- and reversed-phase separation of the four stereoisomers of nadolol using a Chiralpak AD column, optimized with respect to mobile-phase modifiers, flow rates, and column temperatures. The normal-phase method used hexane, ethanol, and diethylamine as mobile-phase components, whereas the reversed-phase method used water, ethanol, and diethylamine (J88). Lynam and Nicolas compared the long-term stability and enantioselectivity of two matched Chiralcel OD columns by normal-phase LC (hexane with alcoholic modifiers) and SFC (CO2 with modifiers), with trans-stilbene oxide and carbobenzyloxy phenylalaninol as the chiral analytes. Although the columns were quite stable in both systems, better enantiomeric resolution was obtained by SFC (J89). Hermansson and co-workers employed eight NSAIDs (carprofen, flurbiprofen, naproxen, tiaprofen, fenoprofen, ibuprofen, indoprofen, ketoprofen) as model compounds for a thorough study of organic and inorganic modifier-induced effects on enantioselectivity and retention on a Chiral-AGP column. Dramatic increases in enantioselectivity were nearly always observed with increasing concentrations of amine modifiers and were generally observed with increasing concentrations of inorganic cations (J90). They also studied the chromatographic properties of 29 basic drugs on an R1-acid glycoprotein column while varying the pH and the concentration of inorganic ions in the mobile phase; the results indicated that the relative contribution of ion exchange and ion pairing to the retention process is greatly dependent on mobile-phase pH and ion concentration (J91). Finally, Karlsson et al. investigated the influence of charged and uncharged modifiers and mobile-phase pH on the separation of (R)- and (S)felodipine and found that a high mobile-phase pH (7.6) and the addition of 2-propanol as organic modifier gave the highest enantioselectivity (1.3) with a silica-based Chiral-AGP column (J92). Geometric Isomers. Relative to enantiomers, geometrical isomer separations received less attention by researchers. Nevertheless, several noteworthy papers were published. Sander and Wise reviewed shape selectivity in reversed-phase HPLC for the separation of planar and nonplanar solutes, placing emphasis on practical choices that are available to control selectivity and optimize separations for isomers and related mixtures (J93). Dobson et al. reviewed silver ion chromatography of lipids and fatty acids (J94). Separations were divided according to number, geometry, and position of double bonds as well as acyl positional isomers for triacylglycerols. Wyss reviewed the chromatographic analysis of biomedically important retinoids (J95). HPLC with UV detection was found still to be the method of choice from the sensitivity, selectivity, sample throughput, and robustness points of view. Several new stationary phases were investigated for the separation of geometric isomers. Korakas and Valko compared

the retention behavior of lipidic amino acids and peptides on C18 and the newly developed Supelcosil LC-ABZ stationary phases (J96). Both stationary phases could be used to separate geometric isomers; however, they found that much lower concentrations of organic mobile phase were needed when using the Supelcosil stationary phase, thus reducing the possibility of observing detrimental silanol effects. Fukumoto et al. investigated the chromatographic separation of geometric isomers using highly oriented polymer-immobilized silica gels (J97). Emenhiser et al. investigated the capability of a novel polymeric C30 stationary phase to resolve cis-trans carotenoid isomers in reversed-phase HPLC (J98). A new method to prepare spherical carbon beads was introduced by Nagaoka et al. in which the stationary phase was prepared by graphitizing spherical particles of cellulose (J99). As with conventional carbon packings charge-transfer interactions facilitated the separation of positional isomers. Weber et al. evaluated a novel porous carbon-clad zirconia stationary phase (J100). It was found to differ greatly from conventional supports in its chromatographic selectivity, and geometric isomers were separated with much higher resolutions compared to C18 silica. Hesselink et al. investigated the use of a wide-pore C18 bonded phase and found that the separation of a broad range of PAHs in different sample matrixes was possible on this novel phase (J101). Difeo and Shuster investigated the use of mixed-mode gradient HPLC analysis of a tyrosine kinase inhibitor, its isomers, and other potential impurities (J102). They used a Supelcosil LC-SCX cationexchange column in series with a Nova-Pak dimethyloctadecyl silyl analytical column and predicted that this combination of columns would be particularly useful for pharmaceutical products whose collective mixtures of precursors and potential degradation products often span a wide range on the polarity scale. After examining the effects of ammonia concentration and overall mobile phase on solvent strength and selectivity, Ho and Candy separated hemin, protoporphyrin IX, Mn protoporphyrin IX, Co protoporphyrin IX, Sn protoporphyrin IX, and Zn protoporphyrin IX isocratically in 50%. Rosenfeld and Fang (M16) reported the use of a poly(styrene-divinylbenzene) polymer for the simultaneous sorption and derivatization of prostaglandins. They noted that the solid phase also retained the derivatized solutes while a substantial amount of excess reagent was selectively eluted. Kou et al. (M17, M18) reported the development of two novel derivatization agents having both a chromophore and a group that is chemically cleavable, allowing the reagent to be readily removed by acid treatment. They reported the use of 2,4,6-trichlorophenol (M17) as one model analyte and iodide anion as another (M18). As diode lasers become more popular, methods are being developed for the derivatization of a number of compounds which would allow visible-wavelength laser-induced fluorescence detection. Karnes et al. (M19) investigated several possible derivatizing agents for amines and carboxylic acids, and Mank et al. (M20) described the synthesis and use of several red-absorbing labels containing a single succinimidyl ester functionality. This is likely an area where much more work will be occurring. There was again activity in derivatization of compounds which would allow enhanced detection by mass spectrometry! Vreeken et al. (M21) reported a postcolumn Diels-Alder derivatization of vitamin D3 and its metabolites which improved the limits of detection by 7-70 times. Mamer et al. (M22) described the synthesis and application of several reagents for introducing phosphonium, ammonium, or sulfonium functions into a peptidoleukotriene. They found this derivatization enhances chemical stabilities and significantly increases responses in fast atom bombardment and continuous-flow liquid secondary ion mass spectrometry. Lucy and Ye (M23) reported a new scheme using a displacement mechanism, where a metal ion displaces Mg2+ from the Mg(CDTA)2- complex. The liberated magnesium then reacts with 8-hydroxyquinoline-5-sulfonic acid to form an intensely fluorescent complex. In spite of the inherent difficulties, immobilized enzymes continue to be popular as pre- and postcolumn derivatization reagents. Jen and Tsai (M24) reported the use of β-glucosidase immobilized on an amine bonded-phase silica for the precolumn derivatization of glucuronide/sulfate metabolites of benzene. They used a switching valve to control the passage of the sample and the eluent into the reactor to minimize damage to the enzymes by the mobile phase. Ohta et al. (M25) described a clever scheme using immobilized carbonic anhydrase to retain sulfonamide drugs with an unsubstituted sulfonamide group, and these retained drugs were subsequently eluted and separated on a reversed-phase column. The use of micellar media for derivatization reactions also has certain advantages; specifically, they can be useful for solubilization of hydrophobic reagents and can speed reaction kinetics. While no fundamental studies of these properties were reported during this review period, Garcia-Alvarez-Coque et al. (M26) performed an azo dye precolumn derivatization of sulfonamides in a 0.05 M SDS/24.% pentanol micellar mobile phase which was subsequently used for separation. Traore et al. (M27) performed a fundamental spectroscopic study of 9-substituted fluorescent quinolizinocoumarin derivatives

(luminarins) to better understand and predict the wide variations in emissions observed in different mobile phases. Amines are likely the most heavily studied group for chemical derivtization because of their biological, industrial, and environmental importance. There are many classic reactions, and virtually every detection technique has been applied to the analysis of these compounds. There was a great deal of activity in this area during this review period, and for convenience, we have grouped these reports approximately by detection technique. Polyaromatic hydrocarbon tags provide a highly sensitive fluorescent tag and continue to be studied. During this review period there were new reports of acenaphthene reagents (M28) and of 2-aminoanthracene (M29). 9-Fluorenylmethyl chloroformate continues to be a popular derivatizing agent for amines, and there were also two reports of new studies of this reagent. Kirschbaum et al. (M30) reported precolumn derivatization of biogenic amines and amino acids, and they added heptylamine to the solution to react with excess reagent. Bartok et al. (M31) developed an automated two-step derivatization scheme using o-phthaldialdehyde/3-mercaptopropionic acid for primary amines and 9-fluorenylmethyl chloroformate for secondary amino acids. Cohen et al. (M32-M34) introduced 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate as a precolumn reagent for amino acids, compared its use with phenylisothiocyanate (M32), and published two applications papers describing its use (M33, M34). Two other new fluorescent agents were reported for amines and amino acids. Sodium benzoxazole-2-sulfonate is not fluorescent but reacts with amines and amino acids to give derivatives which exhibit intense blue fluorescence (M35). A series of oxycarbonyl chlorides were also prepared and evaluated in comparison with the established reagent 9-fluorenylmethoxycarbonyl chloride (M36). Three new reports appeared of the use of UV-absorbing reagents for either pre- or postcolumn reactions with amines and amino acids. Supposedly these would offer less selectivity in detection and higher (poorer) limits of detection. 9-Isothiocyanatoacridine (M37), 1-fluoro-2,4-(dinitrophenyl)-5-alanine amide (M38), and 1,2-naphthoquinone-4-sulfonate (M39) were all described. After eight years of writing this review, it appears it would be highly useful for a comprehensive, thorough experimental comparison of the many methods that have been proposed for amino acids to be performed and published. Electrochemical detection of derivatized amino acids and especially peptides is also of continuing interest. Turiak and Volicer (M40) published a very nice work on the stability of o-phthalaldehyde/sulfite derivatives of amino acids and their methyl esters, using a 16-channel coulometric electrode array detector to monitor the decomposition of the derivatives. Wintersteiger et al. (M41) derivatized primary and secondary aliphatic amines with salicylic acid chloride to produce electroactive amide derivatives with good chemical stability. Finally, Kubo et al. (M42, M43) described the use of an in-line reactor containing copper metal for the formation of oxidizable Cu(II)-peptide complexes, and reported detection limits of low nanograms. The use of chemiluminescence as a detection scheme for amino acids continues to generate interest and can give extremely low limits of detection. Jackson and Bobbitt (M44) described the in situ generation of Ru(bpy)3 for the determination of underivatized amino acids, Lee and Nieman (M45) determined dansyl amino acids using Ru(bpy)3-generated chemiluminescence, Toyoo-

ka et al. (M46) described chemiluminescence and fluorescence detection of oxazole-labeled amines and thiols, and Ishida et al. (M47) prepared a new compound, 6-isothicyanatobenzo[g]phthalazine-1,4(2H,3H)-dione, and showed it as a highly sensitive chemiluminescent derivatization reagent for primary and secondary amines. All of these reports described detection limits in the femtomole range! There were also two specific reports of the use of chemiluminescence for the determination of catecholamines. Ragab et al. showed the use of 1,2-diarylethylenediamines (M48), and 1,2-diphenylethylenediamine (M49) as precolumn derivatizing agents and reported detection limits in the lowattomole range! After amines, the class of compounds that received the most interest in new derivatization schemes is the carboxylic acids. Here the most interest was in the description of new fluorescent tags, and all the reports described detection limits in the low-femtomole range. These new reagents include 5-(bromomethyl)fluorescein (M50), 5,6-dimethoxybenzothiazole compounds (M51, M52), 5,6methylenedioxybenzofuran compounds (M53, M54), and a benzohydrazide compound (M55). Retinoic acid (M56) and fatty acids (M57, M58) also received attention. Derivatization of the aldehyde functionality was of considerable interest during this reporting period, with most of the reports being of new fluorescent tags. These include a cyanine fluorophore with a hydrazide functionality (M59), 2-aminothiophenols for aromatic aldehydes (M60), two different benzoxadiazole reagents (M61, M62), and postcolumn photochemical derivatization for phenolic aldehydes (M63). In addition to these fluorometric methods, a chemiluminescence scheme using 4,5-diaminophthalhydrazide (M64), and an electroactive labeling scheme using 2,5-dihydroxybenzohydrazide (M65) were also described. Saccharides are another class of compounds that continue to receive much interest, and here the interest in derivatization is for detection enhancement and often for enhanced retention on reversed-phase stationary phases. Toomre et al. (M66, M67) described a new fluorescent reagent, 2-amino-(6-amidobiotinyl)pyridine for tagging of free oligosaccharides and described retention properties by reversed-phase, size-exclusion, anionexchange, and amino-adsorption mechanisms. Other fluorescent labels include 7-amino-1,3-naphthalenedisulfonic acid (M68), benzamidine (M69), and 8-amino-2-naphthalenesulfonic acid (M70). Two reports of UV chromophores also appeared: postcolumn detection of underivatized polysaccharides by reaction with permanganate (M71) and separation and detection of anthranilate derivatives (M72). Derivatization of thiols is another challenging analytical problem, and again there are biomedical, environmental, and industrial applications. Two new fluorometric methods appeared during this review period. Winters et al. (M73) reported the derivatization of several biological thiols with N-(1-pyrenyl)maleimide, with a lower detection limit of ∼50 fmol. Haj-Yehia et al. (M74, M75) used 2-(4-N-maleimidophenyl)-6-methylbenzothiazole, which they reported to give both good selectivity for thiols and low limits of detection. Di Pietra et al. (M76) described the analysis of glutathione and L-cysteine after precolumn derivatization with ethacrynic acid or its methyl ester. This adds a UV chromophore, but then the excess reagent must be removed by either liquid- or solid-phase extraction. Two other interesting mechanistic papers appeared. Lucy and Dinh (M77) investigated the displacement reaction of Zn-EDTAAnalytical Chemistry, Vol. 68, No. 12, June 15, 1996

551R

PAR which is used as a postcolumn reaction system for metal ions. They found that the kinetics and sensitivity of the reagent are strongly dependent on the nature and the concentration of the auxiliary complexing agent and recommended ethylenediamine as the best choice. Saito et al. (M78) studied the kinetics of the stability of the o-phthalaldehyde-spermine fluorophore and suggested that an on-column formed complex is more stable than that formed by the conventional precolumn method. New reactions and reagents were also reported for a variety of other compounds or functional groups. In the interest of space, only the analyte group will be mentioned; interested readers should then see the original article for the derivatizing group and conditions. These include free hydroxyproline and proline in serum (M79), N-nitrosamines (M80), mono-, di-, and trinucleotides (M81), total reactive isocyanate group (M82, M83), carnitine and acylcarnitines (M84), oxalate (M85), paralytic shellfish toxins (M86), phenols (M87), chlorophenols (M88), 12-lipoxygenase products, hepoxilins and related compounds (M89), and cisplatin and cis-diammineaquachloroplatinum (II) (M90). There is some level of frustration in preparing this review, in that there are still too many reports in the literature using incorrect units for reporting limits of detection. Because of the variable of the injection volume, only absolute detection limits, in either moles or grams, are interpretable by other workers. For a concise discussion of this problem, interested workers are referred to a work by Foley and Dorsey (M91). MICROCOLUMN AND OPEN TUBULAR LC We will again adhere to the convention first introduced with the 1992 Fundamental Review of restricting the term “microcolumn” to open tubular or packed columns with internal diameters of less than 0.5 mm, while referring to columns with internal diameters between 0.5 and 2.0 mm as “microbore”. Microbore LC will not be specifically addressed in this section, but the practical advantages of these columns should not be overlooked. Reduced solvent flow rates in microbore columns make them popular in two-dimensional chromatography, and many are cited in the Multidimensional LC and Column Switching section of this review. Fundamental studies of microcolumn LC included a comparison of conventional HPLC and micro-HPLC with laser-induced fluorescence and MS detection for the analysis fatty acids (N1). Gohlin et al. made a direct comparison of open tubular micro-LC and conventional packed-column LC using identical stationary and mobile phases (N2). These workers confirmed theoretical predictions of greater efficiency in open tubular columns (OTCs), as well as the need for sufficient retention in them. The capacity factors that produced maximum efficiencies in the OTCs were in the 0-2 range, compared to 0-5 for packed columns. Steenackers and Sandra discussed the advantages of OTCs for the analysis of polar solutes (N3). Cortes and Nicholson (N4) noted 200300% increases in efficiencies in enantiomeric separations after reducing column inner diameters to 100-500 µm. The characteristics of reversed-phase parallel current open tubular columns (RP-PC-OTLC) were the subject of two reports (N5, N6). Several classical chromatographic techniques were applied with LC microcolumns. Two-dimensional methods were described by both Holland and Jorgenson (N7) and Kassel et al. (N8). In the first of these reports, Holland and Jorgenson combined a charge separation mechanism in an anion-exchange column and hydro552R


phobic mechanism in a reversed-phase column to obtain 2-D chromatograms of peptides from a tryptic digest of a single bovine chromaffin cell. Kassel et al. combined affinity and reversed-phase microcolumns coupled to electrospray ionization MS for the determination of molecular weight maps of proteins. Ishii and co-workers applied frontal chromatography in 0.5-mm Teflon tubes to which trypsin and chymotrypsin had been immobilized to quantify biospecific interactions suitable for affinity chromatography (N9). The preparation and packing of microcolumns, or coating in the case of OTCs, received considerable attention during the past two years. Broughtflower et al. described a ultrasound method for making packed microcapillaries for capillary electrochromatography and micro-LC (N10). Zimina et al. studied the effect of the kinematic viscosity of the slurry on packing efficiency in packed microcolumns (N11). Slurries containing aqueous solutions of surfactants were found to produce higher efficiencies than the organic solvents used in conventional HPLC. Guo and Colon cast an organic-inorganic hybrid material as a thin glass film onto the inner wails of fused silica (N12). These phases have high surface areas, improved phase ratios, and greater retention characteristics. Finally, Kassel et al. described packed capillary perfusion columns coupled to electrospray ionization MS for the analysis of enzymatic digests (N13). Capillary perfusion columns appear feasible for this application, although 180- and 320-µm-i.d. micro-LC columns are superior at present. A number of reports describing polymer-filled capillaries for micro-LC appeared, including several in which the polymer packing was formed in situ. A high phase ratio, resulting in greater sample capacity, is one of the advantages of these columns. Poppe and co-workers coated silica capillaries with polyacrylate and then formed polymer networks by in situ polymerization of acrylic monomers (N14, N15). These same workers also described an ethoxyethylacrylate phase polymerized in situ (N16), and characterized its retention characteristics for phenolic and aromatic compounds. Li et al. prepared cation-exchange microcolumns in a similar fashion (N17). Several chiral phases were incorporated into microcolumns. R-Chymotrypsin was coated on fused-silica capillaries and used to separate enantiomers of naproxen (N18). Microcrystals of cellulose acetate were packed in 320-µm fused-silica columns (N19). Schurig and co-workers chemically linked a cyclodexrin to dimethylpolysiloxane and coated the chiral polymer on the inside of a 50-µm fused-silica capillary (N20). A number of chemically distinct phases were used in microLC. Saito et al. designed and synthesized octadecylphenyl phases for the separation of C60 and C70 fullerenes (N21). Conversely, a bonded C60 stationary phase was evaluated for PAH separations (N22). Microcolumns fabricated from ion exchangers modified with ion-containing alkyl chains were characterized for their ability to separate PAHs and dansyl amino acids (N23). The small injection volumes and limited sample capacities inherent in micro-LC make detector development a subject of virtually continual interest. Although mass spectrometry is becoming increasingly popular, developments in microchromatography detection are still dominated by optical and electrochemical methods. A Z-shaped UV cell for use with OTCs was described that employs a solvent makeup flow to overcome band broadening that would otherwise result from use of the relatively large volume Z cell (N24). On-column UV detection in 50-µm OT columns was

improved through the use of optical fibers and quick-fit connectors (N25). A packed flow cell was used to enhance fluorometric detection of dansyl amino acids (N26). The same stationary phases used in the 320-µm packed microcolumn were used in the flow cell, and the focusing and environmental effects of the packing in the detector cell greatly improved the sensitivity of late-eluting peaks. Axial illumination of flow cells allowed simultaneous absorbance and fluorescence measurements (N27). Optical path lengths of 1-6 cm were achieved with a unique bend geometry. A flame sulfur chemiluminescence detector for reversed-phase micro-LC was described, and optimized performance characteristics were included in a report by Taylor and co-workers (N28). Finally, the use of thermooptical spectroscopy for micro-LC detection was reviewed by Saz and Diez-Masa (N29). Unlike spectrochemical methods, which must overcome cell path length limitations for application to micro-LC detection, small volumes offer a distinct advantage in electrochemical detection. EC detectors are thus finding widespread use in micro-LC and were the subject of numerous reports. An amperostatic/potentiometric (ASPEN) detector was evaluated for the detection of a variety of phenols after separation on a packed, reversed-phase capillary (N30). Pulsed electrochemical detection (PED) was applied to the determination of thio compounds after separations in microbore and packed microcapillary columns (N31). Mass detection limits of 0.1-0.3 pmol were achieved with the capillary columns. A electrochemical detector cell that is actually the microcolumn end-fitting was described by Kissinger and coworkers (N32). This design minimizes extracolumn void volumes, and a variety of working electrodes can be utilized. Improvements in microcolumn LC instrumentation included separations on a silicon chip (N33). Ocvirk et al. fabricated a split injector, packed microcolumn, frit, and optical detector onto a single silicon chip and evaluated theoretical predictions of efficiency with a separation of fluorescein and acridine orange. Two hundred theoretical plates were obtained in less than 3 min. An improved split flow gradient elution device was coupled with a particle beam LC/MS system (N34). Finally, a unified chromatograph with a single switching valve system was constructed which allows single- or sequential-mode analyses via capillary GC, SFC or micro-LC (N35). TRACE ANALYSIS Trace analytical techniques based on liquid chromatography usually rely on the use of a highly sensitive or selective detector, derivatization to produce an enhanced response in a detector, or sample enrichment. Fundamental developments in these areas, particularly with regard to sample enrichment, are discussed in several other sections of this review, and thus, as in previous Fundamental Reviews, only a selective sampling of trace analysis by liquid chromatography is presented here. The variety of ionization interfaces now available have made LC/MS a virtually routine technique. Two reviews devoted specifically to LC/MS trace analysis were noted. The first (O1) addressed environmental trace analysis specifically and focused on thermospray, particle beam, and atmospheric ionization interfaces; the second on atmospheric ionization via electrospray and chemical ionization (O2). A high-flow pneumatically assisted electrospray source coupled to a reversed-phase LC system was described for the characterization of triazine, phenylurea, and other herbicides (O3). This system was also used to detect acidic

pesticides in water (O4), as was a similar system (O5). HPLC/ MS with thermospray ionization was evaluated for the determination of 108 pesticides and some of their degradation products covering a wide range of structures and polarities (O6). The coupling of high-performance LC methods with elementspecific analyzers such as ICP mass spectrometry (ICPMS) and ICP-atomic emission spectroscopy (ICP-AES) was frequently applied to the determination of trace metal speciation. Applications of HPLC with plasma-MS detection were reviewed by Caruso and co-workers (O7, O8). Heumann et al. described the coupling of HPLC and ICP isotope dilution MS for trace elemental analyses (O9). Anion-exchange chromatography and ICP-AES was used to determine the relative abundances of Cr(III) and Cr(IV) (O10). Ion chromatography with ICP-AES and ICP-MS detection was compared to graphite furnace atomic absorption spectroscopy in another report (O11). Selective derivatizations are still popular for trace analysis by LC, and many such strategies now incorporate solid-phase extraction and enrichment. Fu and Xu described just such a system for trace N-nitrosamines and secondary amines in groundwater, combining adsorption onto activated carbon and fluorogenic derivation for chemiluminescence detection (O12). Microcystins were detected at the femtomole level using an HPLC separation and postcolumn reactor for chemiluminescence detection (O13). Methotrexate and 7-LH-methotrexate in plasma were measured with solid-phase extraction, HPLC separation, postcolumn photoreaction, and fluorometric detection (O14). The detection limit for methotrexate was 0.05 ng/mL. PHYSIOCHEMICAL MEASUREMENTS This section deals with the use of HPLC for studying physiochemical behavior, such as thermodynamic, kinetic, and conformational properties of solutes. Selected papers on thermodynamics as related to separation mechanisms are also covered. Readers interested in this topic may want to consult the corresponding section in the Size Exclusion Chromatography review in this issue. Partition Coefficients/Hydrophobic Measurements. During this review period, the use of HPLC to estimate partition coefficients (P) and hydrophobicity parameters using reversedphase HPLC continues to be an active area for characterizing biologically active compounds. This information is typically used to establish quantitative structure/activity relationships (QSARs). Because of the connectivity between log P and the logarithm of the capacity factor (log k′), HPLC is a rapid method of estimating partition coefficients for QSAR studies. Typically, log k′ is measured as a function of mobile-phase composition using a reversed-phase column, and log k′ in pure water (log kW) is obtained from extrapolation. This value is then related to log P data. With this approach, partition coefficients can be measured on a number of solutes simultaneously without the need of purification. Dorsey and Khaledi (P1) presented a review on HPLC methods for determining octanol partition coefficients and discussed solution thermodynamics of the partitioning process and implications for biological partitioning processes. Hsieh and Dorsey (P2) also reported on the importance and implications of estimating biological activity with either octanol/water partition coefficients or HPLC retention parameters. They demonstrated that solute partitioning into densely bonded reversed-phase stationary phases mimics partitioning into a biomembrane better than does bulkAnalytical Chemistry, Vol. 68, No. 12, June 15, 1996

553R

phase octanol. Valko et al. (P3) reviewed the dependency of k′ on mobile-phase composition and concluded that there is probably no one best equation for extrapolating all retention data to a pure solvent for purposes of predicting log P values from chromatographic data. Kaliszan (P4) reviewed the use of quantitative structure/retention relations to determine hydrophobicity of drugs and xenobiotics by HPLC. Cichna et al. (P5) demonstrated that a solvent-generated liquid/liquid chromatographic system improves accuracy and precision of octanol/water partition coefficients. Nasal et al. (P6) introduced a new reversed-phase material, an immobilized artificial membrane (IAM), for predicting bioactivity in terms of human skin permeation by steroid hormones. This group (P7) also used the IAM column to determine a hydrophobicity parameters of a number of drugs. Pagliara and co-workers (P8) evaluated a reversed-phase packing (Supelcosil LC-ABZ) for predicting lipophilicity measurements. Henczi et al. (P9) developed a modified micro-shake-flask method to obtain a regression equation between log P and log k′ values. Kaune et al. (P10) reported on the use of gradient elution HPLC for predicting log P values. A computer program was developed and evaluated by Fekete et al. (P11) for predicting pKa and log P values based on solute structures. Makovskaya et al. (P12) determined log P values using water as the mobile phase together with a computer software package designed for optimization and simulation of gradient HPLC systems. Kim (P13, P14) calculated log k′ and log P values directly from three-dimensional structures of derivatives of furan, triazine, 2-pyrazine, and 2-pyridine using comparative molecular field analysis. Luco et al. (P15) used HPLC to determine hydrophobicity parameters of several chalcones and flananones with methanol/ water mobile phases of different compositions and with trace quantities of decylamine and octanol added to the eluent to minimize silanophilic interactions present in the alkylsilane-bonded phases. This study was used to obtain hydrogen-bonding information of these compounds. Abraham and colleagues (P16) obtained log k′ and log P data from HPLC to study hydrogen bonding of solutes. Yamagami and co-workers used reversedphase HPLC to determine hydrophobicity parameters for benzyl N,N-dimethylcarbamates (P17), heteroaromatic solutes (P18), monosubstituted pyrimidines (P19), and pyrazines (P20). Hearn’s group (P21) presented four new scales of amino acid hydrophobicity coefficients derived from reversed-phase retention data of 1738 peptides. The scales were based on different stationary phases (C18, C8, C4) and mobile-phase systems, water/ acetonitrile and water/acetonitrile/propanol). Yamaki et al. (P22) studied hydrophobic interactions of 115 peptides on a microspherical carbon packing. Rothemund et al. (P23) determined log kW values of 14 fibrinogen receptor antagonist peptides and correlated these results to hydrophobic parameters to the log P of the amino acid side chains. Data from a C8 packing was compared to a polyethylene column. Zou et al. (P24) compared log P values to retention behavior of sulfonic acids using reversed-phase and ion-pair HPLC systems. Baj and Dawid (P25) studied the quantitative structure/retention relationship (QSRR) of dialkyl peroxides using reversed-phase HPLC. Forgacs and Cserhati (P26) determined the hydrophobicity and specific hydrophobic surface area of a nonhomologous series of anticancer drugs by reversed-phase HPLC. This group (P27) also studied the retention behavior of aniline derivatives 554R


on polyethylene-coated packings and C18 columns. For a set of β-adrenergic blocking drugs, Hamoir and Massart (P28) derived a QSSR with log P using a normal-phase (cyanopropyl) column. Reversed-phase HPLC was used to estimate log P values for 1,3-thiazolidin-4-ones (P29) and dihydropyridine Ca antagonists (P30). Using reversed-phase HPLC, Ritter et al. (P31) determined log P values of a number of environmentally important organic compounds, such as phenol, indole, biphenyl, and naphthalene derivatives, polycyclic aromatic compounds, and polyfunctional haloaromatics. From reversed-phase HPLC retention data, Jiang et al. (P32, P33) estimated the water solubility of pesticides. Both log P and pKa values were determined for a number of nucleosides (P34) and 20 compounds of pharmaceutical interest (P35). Values of pKa were determined for leukotriene B4 and prostaglandin B2 (P36) and for the R-amino group of different N-terminal amino acid residues (P37). Hendriks et al. (P38) developed models for taking into account changes in pH and organic modifier content in reversed-phase HPLC. By the use of reversed-phase HPLC, log k′ data were found to correlate with log P values for acyclovir esters (P39), N-acylamino acids (P40), β-adrenoceptor blocking agents (P41), anticonvulsants (P42), bitter principles of plants (P43), flavonoids (P44), fluorinecontaining amide herbicides (P45), o-hydroxybenzenesulfonanalides (P46), polyamino carboxylates (P47), teicoplanin antibiotics (P48), and 9H-thioxanthene and 9H-xanthene derivatives (P49). Association and Stability Constants. The Hummel-Dreyer method was used for determining association constants of inclusion complexes of steroid hormones with cyclodextrins (P50). Loukas et al. (P51) used HPLC to determine the stability constant of a cyclodextrin inclusion complex of an organophosphorus insecticide. Sutheimer et al. (P52) described a gradient-elution cation-exchange HPLC method for measuring the formation constant of Al(III) complexes. An HPLC method for measuring complex formation equilibria by competitive chelation, reported by Chellquist and Searle (P53), was used to measure the formation constant of Gd(III) 2,6-bis(aminomethyl)pyridinetetraacetate. Bian and colleagues (P54) determined the stability constant of Zn(II) porphyrin. Zou et al. (P55) studied the effects of molecular structure on the solute/micelle and solute/stationary phase binding constants in micellar LC. Solute/micelle association constants of polynuclear aromatic hydrocarbons in the presence of alcohols were evaluated by HPLC using micellar mobile phases (P56). Using lectins as protein models, Honda (P57) reviewed and discussed HPLC and capillary electrophoresis methodologies to study carbohydrate/protein interactions. Kaliszan et al. (P58) described the use of HPLC to study the interactions between a1acid glycoprotein (AGP) and 52 basic drugs. HPLC retention parameters were related quantitatively to hydrophobicity and molecular modeling parameters from which a binding site on AGP, common for various classes of drugs, was defined. Wainer’s group (P59) used zonal elution and affinity HPLC to study the different binding characteristics of (R)- and (S)-ibuprofen with HSA. This was done by injecting small amounts of (R)- and (S)-ibuprofen onto an immobilized HSA column in the presence of a mobile phase that contained known concentrations of the two chiral drugs as a competing agent. These studies indicated that the drugs had one common binding site on the immobilized HSA column. The association constants of the drugs were determined.

Loun and Hage (P60) used frontal analysis to determine the strength and degree of binding of (R)- and (S)-warfarin onto an immobilized HSA column. Free energy and entropy of binding were measured. In a related study, these authors (P61) characterized the binding of thyroid hormones and related compounds at the warfarin and indole sites of HSA. This was accomplished by continuously applying thyroid hormones or structural analogs to an immobilized HSA column while making injections of sitespecific probe molecules, i.e., (R)-warfarin and L-tryptophan. Equilibrium and thermodynamic parameters were measured. Tiller et al. (P62) described an HPLC/MS method for estimating individual protein-binding affinities of compounds onto immobilized HSA. Ibrahim and Aubry (P63) developed a melaninbased HPLC stationary phase and used it for frontal affinity chromatography to measure the affinity and binding capacity of chlorpromazine and promethazine. Blondelle et al. (P64) used reversed-phase HPLC to determine the binding domains of peptides to a lipid surface by chemical modification of specific amino acid side-chain functional groups. For an R-helical 18-mer peptide, the binding domain in its lipid-induced conformational state was found to be the entire hydrophobic face of the amphipathic R-helix. Thermodynamic Studies. Bellot and Condoret (P65) reviewed modeling of LC equilibria. Miyabe (P66) reported on the measurement of adsorption equilibria, isosteric heat of adsorption, and activation energy of surface diffusion for organic adsorbates. Eltekova (P67) used HPLC to study the structure of mesoporous carbon sorbents and adsorption equilibria of aromatic compounds. These data revealed the presence of micropores and allowed for the estimation of mesopore surface area. Rodrigues et al. (P68) determined adsorption equilibrium isotherms and effective diffusivities of enantiomers separated on cellulose triacetate HPLC columns. LC was used by Martinez and co-workers (P69) to evaluate the sorption and diffusion properties of amino acids on modified divinylbenzene-polystyrene resins. Renard et al. (P70) determined the association rate constant of antigen-antibody reactions at the solid/liquid interface. This was accomplished by studying the adsorption of HSA on monoclonal and polyclonal antiHSA antibodies immobilized on a HPLC silica support using frontal chromatography. Kazakevich and McNair (P71) discussed the thermodynamic definition of dead volume in HPLC and its determination. A method was suggested for the accurate calculation of the dead volume from mobile phase component disturbance peaks. Moeckel (P72) reported that the dead volume of ODS columns, as determined from a homologous series of n-alkanes with pentane or methanol eluents, decreases with increasing temperature. This decrease was caused by thermal expansion of both mobile and stationary phases. Guillaume and Guinchard (P73) described a method of studying the temperature dependence and the effect of mobilephase composition on reversed-phase HPLC retention. Enthalpies and entropies of transfer of benzodiazepines from the mobile to the stationary phase were calculated via van’t Hoff plots. These authors (P74) also studied the thermodynamic behavior of benzodiazepines in acetonitrile/water and methanol/water. Hou and Xu (P75) derived a relationship between excess thermodynamic functions and chromatographic parameters using solution and chromatographic theory. The excess enthalpy and entropy of cephalosporins were determined and were found to

be important in QSAR studies. Roush et al. (P76) used anionexchange HPLC to investigate the retention behavior of cytochrome b5 as a function of temperature and NaCl concentration. Apparent van’t Hoff enthalpies of adsorption were obtained and retention data were interpreted in terms of the stoichiometric displacement model to obtain the number of binding sites in the contact region. Zimmerman and Saionz (P77) studied the retention behavior of p electron-deficient solutes on stationary phases that were prepared from synthetic hosts that selectively bind nitrated aromatic compounds. Enthalpies, obtained from van’t Hoff plots, were found to correlate with corresponding complexation enthalpies measures in solution. Yang and Lu (P78) used chiral HPLC to study the temperature-dependent and acid-catalyzed racemization of 3-O-methyl and 3-O-ethyloxazepam enantiomers. Thermodynamic parameters related to the formation of an activated complex were determined for this system. Kita and Kaneko (P79) used a new type of stationary phase to measure the self-association enthalpy of a pyrazolotriazole azomethine magenta dye. Kang (P80) studied the enthalpic interaction of a series of metal chelates on a reversed-phase column. Silveston and Kronberg (P81) measured the solubility and thermodynamic properties of a series of alkylbenzenzenes in water over a wide temperature range using poly(dimethylsiloxane) coated onto nonporous glass beads as the stationary phase. The thermodynamic data were analyzed in terms of the Flory-Huggins theory giving combinatorial and noncombinatorial contributions to the free energy of transfer. Park and co-workers (P82) used UNIFAC-computed activity and partition coefficients to study the transfer of various homologous series of solutes from aqueous mixtures of methanol, acetonitrile, and THF to alkanes and benzene. This study was used to determine the effects of solute type, mobile-phase composition, chain length of the alkyl-bonded stationary phases, and temperature on retention behavior. Hou and Lu (P83) calculated the activity coefficients of alkylbenzenes using the UNIFAC model for aqueous mixtures of methanol, ethanol, acetonitrile, and THF on a C18 stationary phase. The relationship between k′ and the activity coefficient was established. Kinetic Studies. Su et al. (P84) used HPLC at low temperatures to measure the kinetics and activation energy of the mutarotation of R- and β-N,N′-diacetylchitobiose using silicaimmobilized lysozome as the stationary phase. Subambient normal-phase HPLC was employed by Egekese et al. (P85) to determine the kinetics and activation energy of on-column intramolecular ring closure of an active ester to a cyclic ether. The molecular interconversion between two forms of a macrolide immunosuppressant was studied at subambient temperatures by Nishikawa and co-workers (P86). Soentjens-Werts et al. (P87) investigated the photoisomerization of chlordiazepoxide into its oxaziridine derivative using reversed-phase HPLC at subambient conditions. The kinetics of amine-epoxide reactions was determined by HPLC (P88). HPLC was used to study the reaction kinetics of 2-acetoxy-2-phenylpropane with acetic anhydride (P89). Guan et al. (P90) determined the kinetics of ligand-exchange reaction of Pt(II) complexes. Berger et al. (P91) studied the effect of magnesium concentration on the enzymatic rate of ATPase. Hsieh and colleagues (P92) used MS coupled to HPLC to determine the hydrolysis kinetics Analytical Chemistry, Vol. 68, No. 12, June 15, 1996

555R

of dinucleotides with bovine pancreatic RNase A and the substratespecific hydrolysis of lactose with β-galactosidase. The kinetics of enzyme-catalyzed oligopeptide cleavage was followed by CZE, and the results were compared to data obtained by HPLC (P93). Nunez and Piazza (P94) measured the relative rate of lipoxygenase-catalyzed oxidation of lipids using a polymeric-based packing. Alebic-Kolbah and Wainer (P95) investigated the application of an immobilized enzyme HPLC column to determine enzymatic hydrolysis of L-tryptophan methyl ester to L-tryptophan using R-chymotrypsin immobilized by adsorption onto an artificial membrane support. Renard et al. (P96) studied the adsorption kinetics of HSA on immobilized monoclonal antibodies covalently bound to an HPLC silica packing. In the pharmaceutical industry, HPLC is used extensively to study kinetics of drug hydrolysis, stability, and degradation. Selected papers in these areas include the hydrolysis of amoxicillin catalyzed by metal ions (P97), hydrolysis of metampicillin to ampicillin (P98), alkaline hydrolysis of cefotaxime (P99), hydrolysis of cefuroxime (P100); stability of antineoplaston (P101), flunarizine dihydrochloride (P102), polymyxin B sulfate (P103), famotidine (P104), vancomycin hydrochloride (P105), prochlorperazine (P106), and an intravenous fat emulsion (P107). Biotransformation kinetics of adiponitrile into adipic acid via nitrile hydratase and amidase was reported by Moreau et al. (P108). HPLC was used to study hydrolysis kinetics of Pt(II) complexes (P109), hydrolysis of an organophosphorous insecticide (P110), and hydrolysis of 2′-deoxyuridine (P111). Lai and Vucic (P112) used normal-phase HPLC to determine the degradation kinetics of motor oil vs mileage by monitoring the formation of aromatic compounds, polar species, and polynuclear aromatic hydrocarbons. Conformational Studies. To study the role of conformation in the retention behavior of polypeptides, Hearn’s group determined the elution properties of four different insulins (P113) and insulin A and B chains (P114) as a function of temperature, column residence time, and stationary phase. Hearn and coworkers (P115) reported on the elution properties of a series of amphipathic peptide multimers and concluded that stationary phase-mediated conformational effects can stabilize peptide structure depending on peptide length and column residence time. The amphipathic secondary structure of the peptides were more effectively stabilized by the more hydrophobic C18 stationary phase relative to C4 reversed-phase packings. This group (P116) also investigated the effect of cytochrome c conformation on peak widths using C18 and C4 stationary phases. Hodges et al. (P117) evaluated the use of reversed-phase HPLC as a probe of hydrophobic interactions involved in protein folding and stability. Retention behavior of synthetic analogs of monomeric R-helices and dimeric coiled coil structures correlated well with their stability in solution, as monitored by circular dichroism during guanidine hydrochloride and temperature denaturation studies. This group (P118) also examined the retention behavior of a nonhelical and an R-helical peptide with various linear gradients to determine the effect of peptide conformation on separation selectivity. Krause et al. (P119) correlated the effect of D-amino acid substitution position on helicity with retention time in order to locate amphipathic R-helical structures. Plots of retention time vs the position of the double D-amino acid replacement indicates the presence and location of an amphipathic R-helical secondary 556R


structure in peptides. Studies were also done using nonamphipathic helix-forming peptides as well (P120). Shi et al. (P121-P123) described a characteristic parameter, the Z value of the stoichiometric displacement model, that was used to study changes in molecular conformation of proteins caused by mobile-phase composition and temperature effects; the latter of which can be evaluated from a plot of the Z value vs the reciprocal of absolute temperature. Karger’s group (P124) described the conformational changes of recombinant human growth hormone as a function of organic solvent in reversed-phase HPLC. Salom et al. (P125) investigated the conformational behavior of the optically reversed gramicidin M, an analog of gramicidin A in which the Trp residues are replaced with Phe. This peptide was found to undergo a conformational transition from β-helical monomers to thermodynamically stable doublestranded dimers. Alfredson et al. (P126) studied the conformer interconversion of triostin A and its under-N-methylated synthetic analog as a function of column temperature. A chromatographic model was developed to estimate the kinetics of conformer interconversion. Potaman et al. (P127) used reversed-phase HPLC to detect differences in the secondary structures of two self-complementary oligodeoxyribonucleotides as a function of temperature. Astafieva et al. (P128) described the use of an on-line multiangular light scattering detector to determine size and conformation of proteins separated by reversed-phase HPLC. HPLC was employed by Casarini et al. (P129), and Vilani and Pirkle (P130) to study the conformational enantiomers of hindered naphthyl sulfones using a enantioselective column at subambient conditions. Schure (P131) used computational chemical simulation techniques to generate different conformations of the C18 stationary phase. Schunk and Burke (P132) studied the temperatureinduced conformational changes of C18 packings. Hearn’s group (P133) investigated the conformations of C4 groups in reversedphase HPLC packings, and estimated the positions of these chains with respect to the surface, as well as their mobility. At higher surface densities, the butyl groups were predominantly perpendicular to the surface, while at low-density coverage, they were highly tilted or lying almost parallel to the surface. John G. Dorsey is Professor and Chairman of the Department of Chemistry at Florida State University. He received his Ph.D. degree in analytical chemistry (1979) at the University of Cincinnati and moved to Florida State University in 1994. His research interests are in the areas of fundamental LC, CE, analytical applications of micelles and organized media, flow injection analysis, and old Bordeaux wines. He has about 90 publications in these areas and serves on the Editorial Boards of five analytical and chromatographic journals. Since 1990 he has been a member of the Executive Committee of the ACS Subdivision of Chromatography and Separations Chemistry, has instructed short courses in LC for pharmaceutical and consumer products companies, and has organized chromatography symposia for the Pittsburgh Conference, EAS, FACSS, and ACS Meetings. He is the recipient of the 1993 Award for Distinguished Scientific Research from the University of Cincinnati, and the 1993 Akron Section Award of the American Chemical Society. William T. Cooper is currently Associate Professor of Chemistry, Adjunct Professor of Oceanography, and Director of the Terrestrial Waters Institute (TWaIn) at Florida State University. He is also Co-Chair of the Florida Center for Environmental Studies’ Environmental Chemistry Secretariat. He received a B.S. in chemistry degree from the University of Tennessee, Knoxville, and a Ph.D. in chemistry from Indiana University. His research interests are in environmental biogeochemistry, which includes development of CE and ICR MS methods for characterizing complex, naturally occurring organic substances in surface waters; application of normal bonded phase liquid and supercritical fluid chromatography to complex, heterogeneous environmental and biological samples; characterization of the chemical composition of soil and sedimentary organic matter by NMR spectroscopy; and the use of LC and NMR in studies of microbial degradation and metabolism of toxic organic chemicals.

Barbara A. Siles is currently an Assistant Professor of Chemistry at the College of William and Mary in Williamsburg, VA. She graduated from Thomas More College in Crestview Hills, KY (1989). She obtained a B.S. in chemistry, as well as an A.S. in mathematics. She received a Ph.D. in analytical chemistry (1993) with an additional emphasis on biochemistry from the University of Cincinnati. She has applied for two U.S. patents with her collaborators in relation to the adaptation of a slab gel electrophoresis matrix to CE for the separation of DNA fragments. Her analytical research interests include the synthesis of novel stationary phases and their fundamental investigation in LC and electrochromatography and the development and investigation of new polymeric matrices for the separation of biomolecules using capillary electrophoresis; her biochemical interests include base-pair mismatching of DNA and the study of biochemical mechanisms. Joe P. Foley is an Associate Professor of Chemistry at Villanova University. He received his B.S. in chemistry and chemical physics from Centre College of Kentucky (1978) and his Ph.D. in chemistry from the University of Florida (1983). His research interests are in the fundamental and applied aspects of chemical separations. He has published about 44 papers and 6 book chapters pertaining to CE, MEK, HPLC, and SFC. He also teaches a Short Course on Capillary Electrophoresis. A participant at the 1991 NATO Advanced Study Institute on Theoretical Advances in Chromatography and Related Separation Techniques, Dr. Foley has organized and been invited to participate in numerous scientific symposia for the ACS, the Gordon Research Conferences, the Electrophoresis Society, the Pittsburgh Conference, and FACSS, and has served as a consultant for the health, pharmaceutical, chemical, and petroleum industries. He serves on the Editorial Boards of The Analyst and the Journal of Microcolumn Separations and is the Secretary of the Chromatography and Separations Subdivision of the ACS. Howard G. Barth is a senior research associate of the Corporate Center for Analytical Sciences at the DuPont Experimental Station, Wilmington, DE. He received his B.A. (1969) and Ph.D. (1973) in analytical chemistry from Northeastern University. His specialties include polymer characterization, size exclusion chromatography, and HPLC. He edited Modern Methods of Particle Size Analysis (Wiley, 1984) and coedited Modern Methods of Polymer Characterization (Wiley, 1991). He has also edited five symposium volumes, published in the Journal of Applied Polymer Science, and coedited two ACS symposium volumes. He was associate editor of the Journal of Applied Polymer Science. Howard is cofounder and Chairman of the International Symposium on Polymer Analysis and Characterization, and he is editor-in-chief of the International Journal of Polymer Analysis and Characterization.

LITERATURE CITED BOOKS, REVIEWS, AND SYMPOSIA PROCEEDINGS (A1) Dorsey, J. G.; Cooper, W. T.; Wheeler, J. F.; Barth, H. G.; Foley, J. P. Anal. Chem. 1994, 66, 500R-546R. (A2) Scott, R. P. W. Liquid Chromatography for the Analyst; Chromatography Science Series 67; Dekker: New York, 1994. (A3) Riley, C. N.; Lough, W. J.; Wainer, I. W. Pharmaceutical and Biomedical Applications of Liquid Chromatography; Pergamon: Oxford, UK, 1994. (A4) Subramanian, G., Ed. Process Scale Liquid Chromatography VCH: Weinheim, Germany, 1995. THEORY AND OPTIMIZATION (B1) Hwang, Y.-L. Ind. Eng. Chem. Res. 1995, 34, 2849-64. (B2) Thoemmes, J.; Kula, M. R. Biotechnol. Prog. 1995, 11, 35767. (B3) Lightfoot, E. N.; Athalye, A. M.; Coffman, J. L.; Roper, D. K.; Root, T. W. J. Chromatogr., A 1995, 707, 45-55. (B4) Hayashi, Y.; Matsuda, R. Adv. Chromatogr. 1994, 34, 347427. (B5) Forgacs, E.; Cserhati, T. TrAC, Trends Anal. Chem. 1995, 14, 23-9. (B6) Hagan, R. L. Am. J. Hosp. Pharm. 1994, 51, 2162-75. (B7) Scott, R. P. W. Chromatogr. Sci. Ser. 1994, 67, 93-122. (B8) Davis, J. M. Adv. Chromatogr. 1994, 34, 109-76. (B9) Carr, P. W.; Li, J.; Dallas, A. J.; Eikens, D. I.; Tan, L. C. J. Chromatogr. 1993, 656, 113-33. (B10) Tijssen, R.; Schoenmakers, P. J.; Boehmer, M. R.; Koopal, L. K.; Billiet, H. A. H. J. Chromatogr. 1993, 656, 135-96. (B11) Valko, K.; Snyder, L. R.; Glajch, J. L. J. Chromatogr. 1993, 656, 501-19. (B12) Jandera, P. J. Chromatogr. 1993, 656, 437-67. (B13) Wheeler, J. F.; Beck, T. L.; Klatte, S. J.; Cole, L. A.; Dorsey, J. G. J. Chromatogr. 1993, 656, 317-33. (B14) Lochmueller, C. H.; Reese, C.; Aschman, A. J.; Breiner, S. J. J. Chromatogr. 1993, 656, 3-18. (B15) Sun, Z. L.; Liu, M. C.; Hu, Z. D. Chromatographia 1994, 38, 599-608. (B16) Kaliszan, R. J. Chromatogr. 1993, 656, 417-35. (B17) Kaliszan, R. Mater. Eng. 1995, 9, 87-103. (B18) Yun, K. S.; Zhu, C.; Parcher, J. F. Anal. Chem. 1995, 67, 6139. (B19) Lowrey, A. H.; Famini, G. R. Struct. Chem. 1995, 6, 357-65. (B20) Boehm, R. E.; Martire, D. E. J. Liq. Chromatogr. 1994, 17, 3145-77. (B21) Waite, S. W.; Holzwarth, J. F.; Harris, J. M. Anal. Chem. 1995, 67, 1390-9.

(B22) Bahowick, T. J.; Synovec, R. E. Anal. Chem. 1995, 67, 63140. (B23) Lukulay, P. H.; McGuffin, V. L. J. Chromatogr., A 1995, 691, 171-85. (B24) Horka, M.; Kahle, V.; Krejci, M.; Slais, K. J. Chromatogr., A 1995, 697, 45-52. (B25) Lee, S. T.; Olesik, S. V. Anal. Chem. 1994, 66, 4498-506. (B26) Dolgonosov, A. M. J. Chromatogr., A 1994, 671, 33-41. (B27) Luo, R. G.; Hsu, J. T. Sep. Technol. 1993, 3, 221-9. (B28) Kalinitchev, A. Ind. Eng. Chem. Res. 1995, 34, 2625-33. (B29) Frey, D. D.; Barnes, A.; Strong, J. AIChE J. 1995, 41, 117183. (B30) Fornstedt, T.; Guiochon, G. Anal. Chem. 1994, 66, 2116-28. (B31) Fornstedt, T.; Guiochon, G. A. Anal. Chem. 1994, 66, 268693. (B32) Guan, H.; Stanley, B. J.; Guiochon, G. J. Chromatogr. 1994, 659, 27-41. (B33) Firouztale’, E.; Maikner, J. J.; Deissler, K. C.; Cartier, P. G. J. Chromatogr. 1994, 658, 361-70. (B34) Martin, D. G. ACS Symp. Ser. 1995, No. 593, 78-86. (B35) Gennaro, M. C. Adv. Chromatogr. 1995, 35, 343-81. (B36) Sander, L. C.; Wise, S. A. J. Chromatogr. 1993, 656, 335-51. (B37) Schoenmakers, P. J.; Tijssen, R. J. Chromatogr. 1993, 656, 577-90. (B38) Vanbel, P. F.; Tilquin, B. L.; Schoenmakers, P. J. J. Chromatogr., A 1995, 697, 3-16. (B39) Wang, F. Y.; Yu, Q. J. Process Control 1994, 4, 135-42. (B40) Guillaume, Y.; Guinchard, C. J. Liq. Chromatogr. 1994, 17, 1443-59. (B41) Guillaume, Y.; Guinchard, C. Chromatographia 1995, 41, 847. (B42) Guillaume, Y.; Guinchard, C. Chromatographia 1995, 40, 1936. (B43) Guillaume, Y.; Guinchard, C. J. Liq. Chromatogr. 1995, 18, 3409-22. (B44) Guillaume, Y.; Guinchard, C. J. Chromatogr. Sci. 1995, 33, 204-10. (B45) Fischer, J.; Jandera, P. J. Chromatogr., A 1994, 684, 77-92. (B46) Chaminade, P.; Baillet, A.; Ferrier, D. J. Chromatogr., A 1994, 672, 67-85. (B47) Marengo, E.; Gennaro, M. C.; Abrigo, C.; Dinardo, A. Anal. Chem. 1994, 66, 4229-35. (B48) Chloupek, R. C.; Hancock, W. S.; Marchylo, B. A.; Kirkland, J. J.; Boyes, B. E.; Snyder, L. R. J. Chromatogr., A 1994, 686, 45-59. (B49) Hancock, W. S.; Chloupek, R. C.; Kirkland, J. J.; Snyder, L. R. J. Chromatogr., A 1994, 686, 31-43. (B50) Jennings, L. S.; Teo, K. L.; Wang, F. Y.; Yu, Q. Comput. Chem. Eng. 1995, 19, 567-73. (B51) Felinger, A.; Guiochon, G. AIChE J. 1994, 40, 594-605. (B52) Suwondo, E.; Floquet, P.; Pibouleau, L.; Domenech, S. Chem. Eng. Commun. 1995, 134, 73-85. (B53) Gallant, S. R.; Kundu, A.; Cramer, S. M. Biotechnol. Bioeng. 1995, 47, 355-72. (B54) Gadam, S. D.; Gallant, S. R.; Cramer, S. M. AIChE J. 1995, 41, 1676-86. (B55) Hamoir, T.; Massart, D. L. Anal. Chim. Acta 1994, 298, 31929. (B56) Fekete, J.; Morovjan, G.; Csizmadia, F.; Darvas, F. J. Chromatogr., A 1994, 660, 33-46. (B57) Csokan, P. P.; Darvas, F.; Csizmadia, F.; Valko, K. LC-GC 1994, 12, 40, 42, 44, 46, 48. (B58) Galushko, S. V.; Kamenchuk, A. A.; Pit, G. L. J. Chromatogr. 1994, 660, 47-59. (B59) Martinez-Vidal, J. L.; Parrilla, P.; Fernandez-Alba, A. R.; Carreno, R.; Herrera, F. J. Liq. Chromatogr. 1995, 18, 296989. (B60) Gorburu, J. V. S.; Shelver, W. L.; Shelver, W. H. J. Liq. Chromatogr. 1995, 18, 1957-72. (B61) Ong, T.-H.; Wong, Y.-S.; Woo, S.-O.; Ng, S. Bull. Singapore Natl. Inst. Chem. 1994, 22, 19-29. (B62) Ong, C. P.; Chow, K. K.; Ng, C. L.; Ong, F. M.; Lee, H. K.; Li, S. F. Y. J. Chromatogr., A 1995, 692, 207-12. (B63) De Beer, J. O.; Vandenbroucke, C. V.; Massart, D. L. J. Pharm. Biomed. Anal. 1994, 12, 1379-96. (B64) Kaufmann, P.; Kowalski, B. R.; Alander, J. Chemom. Intell. Lab. Syst. 1994, 23, 331-9. (B65) Kaufmann, P. Chemom. Intell. Lab. Syst. 1995, 27, 105-14. (B66) Lan, W. G.; Chee, K. K.; Wong, M. K.; Lee, H. K.; Sin, Y. M. Analyst 1995, 120(2), 281-7. (B67) Wan, H. B.; Lan, W. G.; Wong, M. K.; Mok, C. Y. Anal. Chim. Acta 1994, 289, 371-80. (B68) Chee, K. K.; Lan, W. G.; Wong, M. K.; Lee, H. K. Anal. Chim. Acta 1995, 312, 271-80. (B69) Rozbeh, M.; Hurtubise, R. J. J. Liq. Chromatogr. 1994, 17, 3351-67. (B70) Andersson, A. M.; Karlsson, A.; Josefson, M.; Gottfries, J. Chromatographia 1994, 38, 715-22. (B71) Matsuda, R.; Hayashi, Y.; Ishibashi, M.; Takeda, Y. J. AOAC Int. 1994, 77, 338-43. (B72) Arnoldsson, K. C.; Kaufmann, P. Chromatographia 1994, 38, 317-24. (B73) Kirkland, K. M. J. Chromatogr., A 1995, 718, 9-26.


557R

(B74) Haupt, D.; Pettersson, C.; Westerlund, D. Fresenius’ J. Anal. Chem. 1995, 352, 705-11. (B75) Penn, S. G.; Liu, G.; Bergstroem, E. T.; Goodall, D. M.; Loran, J. S. J. Chromatogr., A 1994, 680, 147-55. (B76) Wenclawiak, B. W.; Hees, T. J. Chromatogr., A 1994, 660, 61-5. (B77) Vervoort, R. J. M.; Derksen, M. W. J.; Maris, F. A. J. Chromatogr., A 1994, 678, 1-15. (B78) Staahle, L.; Mian, A.; Borg, N. J. Pharm. Biomed. Anal. 1995, 13, 369-76. (B79) Matyska, M.; Kossowski, T. Chem. Anal. 1994, 39(4), 4317. (B80) Hamoir, T.; Bourguignon, B.; Massart, D. L. Chromatographia 1994, 39, 339-45. (B81) Wang, Q. S.; Gao, R. Y.; Yang, B. W.; Fan, D. P. Chromatographia 1994, 38, 187-90. (B82) Bowater, I. C.; McWilliam, I. G. J. Chem. Educ. 1994, 71, 6758. (B83) Klyushnichenko, V. E.; Yakimov, S. A.; Arutyunyan, A. M.; Ivanov, A. E.; Maltsev, K. V.; Wulfson, A. N. J. Chromatogr., B: Biomed. Appl. 1994, 662, 363-9. (B84) Torres-Lapasio, J. R.; Villanueva-Camanas, R. M.; SanchisMallols, J. M.; Medina-Hernandez, M. J.; Garcia-Alvarez-Coque, M. C. J. Chromatogr., A 1994, 677, 239-53. (B85) Hatrik, S.; Hrouzek, J.; Lehotay, J.; Krupcik, J. J. Chromatogr., A 1994, 665, 9-15. (B86) Howard, A. L.; Thomas, C. L. B.; Taylor, L. T. Anal. Chem. 1994, 66, 1432-7. (B87) Lemr, K.; Zanette, M.; Marcomini, A. J. Chromatogr., A 1994, 686, 219-24. (B88) Lintschinger, J.; Kalcher, K.; Goessler, W.; Koelbl, G.; Novic, M. Fresenius’ J. Anal. Chem. 1995, 351, 604-9. (B89) Chaminade, P.; Baillet, A.; Bayloq-Ferrier, D. Analusis 1994, 22, 55-7. (B90) Castillo, J.; Behavente-Garcia, O.; Del Rio, J. A. J. Liq. Chromatogr. 1994, 17, 1497-523. (B91) Han-Xi, S.; Guo-Sheng, Y.; Ru-Yu, G.; Qin-Sun, W. Chromatographia 1995, 40, 303-6. (B92) Pichini, S.; Altieri, I.; Passa, A. R.; Rosa, M.; Zuccaro, P.; Pacifici, R. J. Chromatogr., A 1995, 697, 383-8. (B93) Carratu, B.; Boniglia, C.; Bellomonte, G. J. Chromatogr., A 1995, 708, 203-8. (B94) Vinas, P.; Lopez Erroz, C.; Hernandez Canals, A.; Hernandez Cordoba, M. Chromatographia 1995, 40, 382-6. (B95) Andrisano, V.; Bonazzi, D.; Cavrini, V. J. Pharm. Biomed. Anal. 1995, 13, 597-605. DATA ANALYSIS (C1) Whitman, D. A.; Weber, T. P.; Blackwell, J. A. J. Chromatogr., A 1995, 691, 205-12. (C2) Olsen, B. A.; Sullivan, G. R. J. Chromatogr., A 1995, 692, 14759. (C3) Vervoort, R. J. M.; Derksen, M. W. J.; Maris, F. A. J. Chromatogr., A 1994, 678, 1-15. (C4) Forgacs, E. Anal. Lett. 1994, 27, 1075-93. (C5) Rotar, A.; Kozjek, F.; Medic-Saric, M. Acta Pharm. 1993, 43(3), 157-65. (C6) Altomare, C.; Carotti, A.; Cellamare, S.; Fanelli, F.; Gasparrini, F.; Villani, C.; Carrupt, P. A.; Testa, B. Chirality 1993, 5, 52737. (C7) Haldna, U.; Pentchuk, J.; Righezza, M.; Chretien, J. R. J. Chromatogr., A 1994, 670, 51-8. (C8) Olive, J.; Grimalt, J. O. J. Chromatogr. Sci. 1995, 33, 194203. (C9) Morton, D. W.; Young, C. L. J. Chromatogr. Sci. 1995, 33, 514-24. (C10) Cataldi, T. R. I.; Rotunno, T. Anal. Methods Instrum. 1995, 2, 27-34. (C11) Hayashi, Y.; Matsuda, R.; Poe, R. B. Chromatographia 1995, 41, 66-74. (C12) Szabo, G. K.; Browne, H. K.; Ajami, A.; Josephs, E. G. J. Clin. Pharmacol. 1994, 34, 242-9. (C13) Walsh, S.; Diamond, D. Talanta 1995, 42, 561-72. (C14) Yamamoto, A.; Matsugaga, A.; Ohto, M.; Mizukami, E.; Kayakawa, K.; Miyazaki, M. Analyst 1995, 120(2), 377-80. (C15) Toft, J.; Kvalheim, O. M. Chemom. Intell. Lab. Syst. 1994, 25, 61-75. (C16) Song, J. M.; Lee, C.; Chung, K. S. Bull. Korean Chem. Soc. 1994, 15, 74-8. (C17) Brereton, R. G.; Elbergali, A. K. J. Chemom. 1994, 8, 42337. (C18) Brereton, R. G.; Gurden, S. P.; Groves, J. A. Chemom. Intell. Lab. Syst. 1995, 27, 73-87. (C19) Elbergali, A. K.; Brereton, R. G. Chemom. Intell. Lab. Syst. 1995, 27, 55-71. (C20) Elbergali, A. K.; Brereton, R. G.; Rahmani, A. Analyst 1995, 120(8), 2207-16. (C21) Elbergali, A. K.; Brereton, R. G. Chemom. Intell. Lab. Syst. 1994, 23, 97-106. (C22) Malmquist, G.; Danielsson, R. J. Chromatogr., A 1994, 687, 71-88. (C23) Round, A. J.; Aguilar, M. I.; Hearn, M. T. W. J. Chromatogr. 1994, 661, 61-75. (C24) Johnston, T. E. Anal. Chem. 1995, 67, 2835-41. 558R


(C25) Hendriks, M. M. W. B.; Coenegracht, P. M. J.; Doornbos, D. A. Chemom. Intell. Lab. Syst. 1994, 25, 227-39. (C26) Kaliszan, R. Chemom. Intell. Lab. Syst. 1994, 24, 89-97. (C27) Kaliszan, R.; Nasal, A.; Turowski, M. Biomed. Chromatogr. 1995, 9, 211-5. (C28) Tomlins, K. I.; Gay, C. Food Chem. 1994, 50, 157-65. (C29) Hatrik, S.; Lehotay, J.; Cizmarik, J. Collect. Czech. Chem. Commun. 1995, 60, 960-5. (C30) Baiocchi, C.; Marengo, E.; Roggero, M. A.; Giacosa, D.; Vietto, L.; Toccori, S. Chromatographia 1994, 39, 481-9. (C31) Baiocchi, C.; Marengo, E.; Roggero, M. A.; Giacosa, D.; Giorcelli, A.; Toccori, S. J. Chromatogr., A 1995, 715, 95104. (C32) Raymond, O.; Biolley, J.-P.; Jay, M. Biochem. Syst. Ecol. 1995, 23, 555-65. NORMAL PHASE (D1) (D2) (D3) (D4) (D5) (D6) (D7) (D8) (D9) (D10)

(D11) (D12) (D13) (D14) (D15) (D16) (D17) (D18) (D19) (D20) (D21) (D22) (D23) (D24) (D25) (D26) (D27) (D28) (D29) (D30) (D31)

(D32) (D33) (D34) (D35)

Borowko, M. Chem. Anal. (Warsaw) 1994, 39, 319. Kaczmarski, K.; Zapala, W. Acta Chromatogr. 1995, 4, 70. Dai, C.-Z.; Lu, P.-Z. Chin. Sci. Bull. 1994, 39, 1458. Luebke, M.; le Quere, J.-L.; Barron, D. J. Chromatogr., A 1995, 690, 41. Carlsson, H.; Oestman, C. J. Chromatogr., A 1995, 715, 31. Grimvall, E.; Oestman, C. J. Chromatogr., A 1994, 675, 55. Hamoir, T.; Massart, D. L. J. Chromatogr., A 1994, 673, 1. Hamoir, T.; Massart, D. L. Anal. Chim. Acta 1994, 298, 319. Dorsey, J. G.; Cooper, W. T. Anal. Chem. 1994, 66, 857A. Yang, M.-H.; Chen, I.-L. In International Symposium on Chromatography, 35th Anniv. Res. Group Liq. Chromatogr. Jpn.; Hatano, H., Hanai, T., Eds.; World Scientific: Singapore, Singapore, 1995; pp 599-603. Pesek, J. J.; Matyska, M. T.; Hemphaelae, H.; Christensen, P. J. Liq. Chromatogr. 1995, 18, 2507. Siles, B. A.; Halsall, H. B.; Dorsey, J. G. J. Chromatogr., A 1995, 704, 289. Okamoto, M.; Nobuhara, K.; Ishii, D. J. Chromatogr., A 1995, 697, 153. Wasiak, W. Chem. Anal. (Warsaw) 1994, 39, 325. Trukhanova, N. V.; Volkov, S. A. J. Anal. Chem. (Transl. of Zh. Anal. Khim.) 1995, 50), 775. Whitman, D. A.; Weber, T. P.; Blackwell, J. A. J. Chromatogr., A 1995, 691, 205. Smigol, V.; Svec, F.; Frechet, J. M. J. J. Liq. Chromatogr. 1994, 17, 259. Schleimer, M.; Pirkle, W. H.; Schurig, V. J. Chromatogr., A 1994, 679, 23. Pirkle, W. H.; Terfloth, G. J. J. Chromatogr., A 1995, 704, 269. Terfloth, G. J.; Pirkle, W. H.; Lynam, K. G.; Nicolas, E. C. J. Chromatogr., A 1995, 705, 185. Kirkland, K. M. J. Chromatogr., A 1995, 718, 9. Aboul-Enein, H. Y.; Serignese, V. Biomed. Chromatogr. 1994, 8, 22. Maier, N. M.; Uray, G.; Kleidernigg, O. P.; Lindner, W. Chirality 1994, 6, 116. Levin, M.; Grizodoub, A.; Leontiev, D.; Georgievsky, V. Chromatographia 1995, 40, 321. Treiber, L. R. J. Chromatogr., A 1995, 696, 193. Loere, A.; Szasz, Gy.; Budvari-Barany, Zs. J. Liq. Chromatogr. 1995, 18, 287. Lee, S. T.; Olesik, S. V. J. Chromatogr., A 1995, 707, 217. Hihara, G.; Nakamura, M.; Kobayashi, H.; Miyamae, H.; Wharf, I.; Onyszchuk, M.; Riviere, P.; Riviere.-Baudet., M. Kuromatogurafi 1995, 16, 31. Bagur, G.; Sanchez-Vinas, M.; Gazquez, D. Anal. Chim. Acta 1995, 309, 157. Tan, K.-C.; Hor, T. S. A.; Lee, H. K. J. Liq. Chromatogr. 1994, 17, 3671. Saito, Y.; Ohta, H.; Nagashima, H.; Itoh, K.; Jinno, K.; Pesek, J. J. Symposium of Chromatography, 35th Anniv. Res. Group Liq. Chromatogr. Jpn.; Hatano, H., Hanai, T., Eds.; World Scientific: Singapore, Singapore, 1995; pp 243-50. McKinney, D. E.; Clifford, D. J.; Hou, L.; Bogdan, M. R.; Hatcher, P. G. Energy Fuels 1995, 9, 90. McKinney, D. E.; Clifford, D. J.; Hou, L.; Bogdan, M. R.; Hatcher, P. G. Prepr. Pap.sAm. Chem. Soc., Div. Fuel Chem. 1994, 39, 835. Desbene, P. L.; Desmazieres, B. J. Chromatogr., A 1994, 661, 207. Drexler, D.; Ballschmiter, K. Fresenius’ J. Anal. Chem. 1994, 348, 590.

REVERSED PHASE (E1) Smith, R. M., Ed. “Retention and Selectivity in Liquid Chromatography; Journal of Chromatography Library 57; Elsevier: Amsterdam, 1995. (E2) Bolck, A.; Smilde, A. K..; Bruins, C. H. P.; Coenegracht, P. M. J.; Doornbos, D. A. InCINC’94sFirst Int. Chemom. InterNet Conf. [Elecronic Conference]. 1994 (Issue Avail. http:// www.emsl.pnl.gov:2080/docs/incinc.chromat.ABdoc.html. (E3) Anderson, D. J. Anal. Chem. 1995, 67(12), 475R-86R. (E4) Dorsey, J. G.; Cooper, W. T. Anal. Chem. 1994, 66(17), 857A67A. (E5) Heron, S.; Tchapla, A. Analusis 1993, 21(8), 327-47.

(E6) Petro, M.; Berek, D. Chromatographia 1993, 37(9-10), 54961. (E7) Smith, R. M. J. Chromatogr. Libr. 1995, 57, 1-46. (E8) Smith, R. M. J. Chromatogr. Libr. 1995, 57, 145-69. (E9) West, S. D. J. Chromatogr. Libr. 1995, 57, 297-336. (E10) Snder, L. C.; Wise, S. A. J. Chromatogr. Libr. 1995, 57, 33769. (E11) Pesk, J. J.; Williamsen, E. J. J. Chromatogr. Libr. 1995, 57, 371-401. (E12) Bolck, A.; Smilde, A. K. J. Chromatogr. Libr. 1995, 57, 40349. (E13) Lochmueller, C. H.; Reese, C.; Hsu, S.-H. J. Chromatogr. Sci. 1995, 33(11), 640-6. (E14) Galushko, S. V.; Kamenchuk, A. A.; Pit, G. L. J. Chromatogr. 1994, 660(1-2), 47-59. (E15) Hamoir, T.; Massart, D. L.; King, W.; Kokot, S.; Douglas, K. J. Chromatogr. Sci. 1993, 31(10), 393-400. (E16) Cupid, B. C.; Nicholson, J. K.; Davis, P.; Ruane, R. J.; Wilson, I. D.; Glen, R. C.; Rose, V. S.; Beddell, C. R.; Lindon, J. C. Chromatographia 1993, 37(5-6), 241-9. (E17) Chaminade, P.; Baillet, A.; Ferrier, D. J. Chromatogr., A 1994, 672(1-2), 67-85. (E18) Nowotnik, D. P.; Narra, R. K. J. Liq. Chromatogr. 1993, 16(18), 3919-32. (E19) Barbosa, J.; Sanz-Nebot, V. Anal. Chim. Acta 1993, 283(1), 320-5. (E20) Seaver, C.; Sadek, P. LC-GC 1994, 12(10), 742. (E21) Boehm R. E.; Martire, D. E. J. Phys. Chem. 1994, 98(4), 131727. (E22) Guillaume, Y.; Guinchard, C. J. Liq. Chromatogr. 1994, 17(13), 2809-20. (E23) Guillaume, Y.; Guinchard, C. Chromatographia 1995, 41(1/ 2), 84-7. (E24) Guillaume, Y.; Guinchard, C. J. Liq. Chromatogr. 1995, 18(17), 3409-22. (E25) Sentell, K. B.; Ryan, N. I.; Henderson, A. N. Anal. Chim. Acta 1995, 307(2-3), 203-15. (E26) McGuffin, V. L.; Evans, C. E.; Chen, S. H. J. Microcolumn Sep. 1993, 5(1), 3-10. (E27) Park, J. H.; Dallas, A. J.; Chau, P.; Carr, P. W. J. Phys. Org. Chem. 1994, 7(12), 757-69. (E28) Abraham, M. H.; Roses, M. J. Phys. Org. Chem. 1994, 7(12), 672-84. (E29) Cheong, W. J.; Choi, J. D. Bull. Korean Chem. Soc. 1994, 15(10), 868-73. (E30) Park, J. H.; Dallas, A. J.; Chau, P.; Carr, P. W. J. Chromatogr., A 1994, 677(1), 1-9. (E31) Reta, M. R.; Anunziata, J. D.; Cattana, R. I.; Siber, J. J. Anal. Chim Acta 1995, 306(1), 81-9. (E32) Barbosa, J.; Berges, R.; Sanz-Nebot, V. J. Liq. Chromatogr. 1995, 18(17), 3445-63. (E33) Hellal, F.; Phan-Tan-Luu, R.; Siouffi, A. M. J. Liq. Chromatogr. 1994, 17(13), 2845-69. (E34) Bosch, E.; Bou, P.; Roses, M. Anal. Chim. Acta 1994, 299(2), 219-29. (E35) Levin, M.; Grizodoub, A.; Leontiev, D.; Georgievsky, V. Chromatographia 1995, 40(5/6), 321-8. (E36) Dzido, T. H.; Engelhardt, H. Chromatographia 1994, 39(12), 67-70. (E37) Heron, S.; Tchapla, A. Analusis 1993, 21(6), 269-76. (E38) Chen, S.; Pietrzyk, D. J. J. Chromatogr., A 1994, 671(1-2), 73-82. (E39) Geng, X. D.; Regnier, F. E. Chromatographia 1994, 38(3-4), 158-62. (E40) Cheong, W. J. Bull. Korean Chem. Soc. 1994, 15(1), 15-20. (E41) Miyabe, K.; Suzuki, M. AIChE J. 1995, 41(3), 536-47. (E42) Buszewski, B.; Jaroniec, M.; Gilpin, R. K. J. Chromatogr., A 1994, 668(2), 293-9. (E43) Seibert, D. S.; Poole, C. F. Chromatographia 1995, 41(1/2), 51-60. (E44) McCrossen, S. D.; Simpson, C. F. J. Chromatogr., A 1995, 697(1+2), 53-8. (E45) McCalley, D. V. J. Chromatogr., A 1995, 708(2), 185-94. (E46) Lee, S. T.; Olesik, S. V. Anal. Chem. 1994, 66(24), 4498506. (E47) Cui, Y.; Olesik, S. V. J. Chromatogr., A 1995, 691(1-2), 15162. (E48) Yarovsky, I.; Aguilar, M.-I.; Hearn, M. T. W. J. Chromatogr. 1994, 660(1-2), 75-84. (E49) Yarovsky, I.; Aguilarn M.-I.; Hearn, M. T. W. Anal. Chem. 1995, 67, 2145-53. (E50) Klatte, S. J.; Beck, T. L. J. Phys. Chem. 1995, 99(43), 1602432. (E51) Sentell, K. B.; Bliesner, D. M.; Shearer, S. T. Spec. Publ.-R. Soc. Chem. 1994, 139 (Chemically Modified Surfaces), 190202. (E52) Scholten, A. B., de Haan, J. W.; Claessens, H. A.; van de Ven, L. J. M.; Cramers, C. A., Anal. Chem. 1994, 66(22), 408592. (E53) Scholten, A. B.; de Han, J. W.; Claessens, H. A.; van de Ven, L. J. M.; Cramers, C. A., J. Chromatogr., A 1994, 688(1+2), 25-9. (E54) Verhulst, H. A. M.; van de Ven, L. J. M.; de Haan, J. W.; Claessens, H. A.; Eisenbeiss, F.; Cramers, C. A. J. Chromatogr., A 1994, 687(2), 213-21.

(E55) Bayer, E.; Baumeister, E,; Tallarek, U.; Albert, K.; Guiochon, G. J. Chromatogr., A 1995, 704(1), 37-44. (E56) Hansen, R. L.; Harris, J. M. Anal. Chem. 1995, 67(3), 492-8. (E57) Uhl, S.; Rempfer, K.; Egelhaaf, H.-J.; Lehr, B.; Oelkrug, D. Anal. Chim. Acta 1995, 303(1), 17-23. (E58) Ciolino, L. A.; Dorsey, J. G. J. Chromatogr., A 1994, 678(2), 201-12. (E59) Brown, V. A.; Barrett, D. A.; Shaw, P. N.; Davies, M. C.; Ritchie, H. J.; Ross, P.; Paul, A. J., Watts, J. F. Surf. Interface Anal. 1994, 21(1), 263-73. (E60) Ludolph, B. S.; Jeng, C.-Y.; Chu, A. H. T.; Langer, S. H. J. Chromatogr. 1994, 660(1-2), 3-15. (E61) Cserhati, T. Anal. Lett. 1994, 27(13), 2615-37. (E62) Forgacs, E. Anal. Chim. Acta 1994, 296(3), 235-41. (E63) Breuer, M. R. P.; Claessens, H. A.; Cramers, C. A. Chromatographia 1994, 38(3-4), 137-46. (E64) van Straten, M. A.; Lynch, R. J.; Claessens, H. A. LC-GC 1995, 13(6), 488-498. (E65) Bourguignon, B.; Massart, D. L. Anal. Chim. Acta 1993, 282(1), 33-45. (E66) Vervoort, R. J. M.; Derksen, M. W. J.; Maris, F. A. J. Chromatogr., A 1994, 678(1), 1-15. (E67) Trushin, S. A.; Kever, J. J.; Vinogradova, L. V.; Belenkii, B. G. J. Microcolumn Sep. 1991, 3(3), 185-90. (E68) Hill, D. W.; Kind, A. J. J. Liq. Chromatogr. 1993, 16(18), 39464. (E69) Moeckel. H. J.; Dreyer, U. Chromatographia 1993, 37(3-4), 179-84. (E70) Kirkland, J. J.; van Straten, M. A.; Claessens, H. A. J. Chromatogr., A 1995, 69(1-2), 3-19. (E71) Scholl, J. P. J. Liq. Chromatogr. 1994, 17(16), 3369-82. (E72) Witkowska-Kita, B.; Podgorny, A.; Sajewicz, M.; Kowalska, T. Acta Chromatogr. 1994, 3, 70-83. (E73) Heron, S.; Tchapla, A. Chromatographia 1993, 36, 11-8. (E74) Tchapla, A.; Heron, S. J. Chromatogr., A 1994, 684(2), 17588. (E75) Tsukahara, S.; Saitoh, K.; Suzuki, N. Anal. Sci. 1994, 10(4), 561-5. (E76) Buszewski, B.; Galushko, S. V. Acta Chromatogr. 1995, 4, 3349. (E77) Miyabe, K.; Suzuki, M. J. Chem. Eng. Jpn. 1994, 27(6), 7859. (E78) Miyabe, K.; Suzuki, M. AIChE J. 1995, 41(3), 548-58. (E79) Emenhiser, C.; Sander, L. C.; Schwartz, S. J. J. Chromatogr., A 1995, 707(2), 205-16. (E80) Jinno, K.; Lin, Y. Chromatographia 1995, 41(5/6), 311-7. (E81) Kirkland, J. J.; Henderson, J. W. J. Chromatogr. Sci. 1994, 32(11), 473-80. (E82) Wirth, M. J.; Fatunmbi, H. O. LC-GC 1994, 12(3), 222, 226, 228. (E83) Guo, Y.; Colon, L. A. Anal. Chem. 1995, 67(15), 2511-6. (E84) Moriyama, H.; Anegayama, M.; Komiya, K.; Kato, Y. J. Chromatogr., A 1995, 691(1-2), 81-9. (E85) Jinno, K.; Nakamura, H. Chromatographia 1994, 39(5/6), 285-93. (E86) O’Gara, J. E.; Alden, B. A.; Walter, T. H.; Petersen, J. S.; Niederlaender, C. L.; Neue, U. D. Anal. Chem. 1995, 67(20), 3809-13. (E87) Walshe, M.; Kelly, M. T.; Smyth, M. R.; Ritchie, H. J. Chromatogr., A 1995, 708(1), 31-40. (E88) Thienpont, A.; Felix, G. Chromatographia 1993, 37(9-10), 505-10. (E89) Boss, K.-S.; Rudolph, A.; Vielhauer, S.; Walfort, A.; Lubda, D.; Eisenbeiss, F. Fresenius’ J. Anal. Chem. 1995, 352(7-8), 68490. (E90) Numura, N.; Itoh, H.; Kinoshita, T. J. Chromatogr., A 1995, 689(2), 203-10. (E91) Pesek, J. J.; Matyska, M. T.; Hemphaelae, H.; Christensen, P. J. Liq. Chromatogr. 1995, 18(13), 2507-26. (E92) Kasturi, P.; Buszewski, B.; Jaroniec, M.; Gilpin, R. K. J. Chromatogr. 1994, 659(2), 261-5. (E93) Buszewski, B.; Jaroniec, M.; Gilpin, R. K. J. Chromatogr., A 1994, 673(1), 11-9. (E94) Czajkowska, T.; Hrabovsky, I.; Buszewski, B.; Gilpin, R. K.; Jaroniec, M. J. Chromatogr., A 1995, 691(1-2), 217-24. (E95) Houbenova, A.; Claessens, H. A.; De Haan, J. W.; Cramers, C. A.; Stulik, K. J. Liq. Chromatogr. 1994, 17(1), 49-68. (E96) Nasuto, R.; Rozylo, J. K. Acta Chromatogr. 1995, 4, 50-63. (E97) Ihara, H.; Nakamura, N.; Nagaoka, S.; Hirayama, C. Anal. Sci. 1995, 11(5), 739-42. (E98) Siles, B. A.; Halsall, H. B.; Dorsey, J. G. J. Chromatogr., A 1995, 704(2), 289-305. (E99) Schmid, J.; Albert, K.; Bayer, E. J. Chromatogr., A 1995, 694(2), 333-45. (E100) Juskowiak, B. J. Chromatogr., A 1994, 668(2), 313-21. (E101) Jedrzjeewski, P. T.; Taylor, L. T. J. Chromatogr. Sci. 1995, 33(8), 438-45. (E102) Arenas, R. V.; Foley, J. P. Analyst (Cambridge, U.K.) 1994, 119(6), 1303-14. (E103) Eleveld, J. T.; Claessens, H. A.; Ammerdorffer, J. L.; van Herk, A. M.; Cramers, C. A. J. Chromatogr., A 1994, 677(2), 21127. (E104) Smigol, V.; Svec, F.; Frecht, J. M. J. Anal. Chem. 1994, 66(23), 4308-15. (E105) Hosoya, K.; Kimata, K.; Araki, T.; Tanaka, N.; Frechet, J. M. J. Anal. Chem. 1995, 67(11), 1907-11.


559R

(E106) Linag, Y. C.; Svec, F.; Frechet, J. M. J. J. Polym. Sci., A: Polym. Chem. 1995, 33(15), 2639-46. (E107) Hosoya, K.; Sawada, E.; Kimata, K.; Araki, T.; Tanaka, N. J. Chromatogr. 1994, 662(1), 37-47. (E108) Hosoya, K.; Kageyama, Y.; Yoshizako, K.; Kimata, K.; Araki, T.; Tanaka, N. J. Chromatogr., A 1995, 711(2), 247-55. (E109) Murayama, K.; Nakamura, H.; Takahashi, K.; Yoshida, A. Anal. Sci. 1994, 10(5), 815-6. (E110) Weber, T. P.; Jackson, P. T.; Carr, P. W. Anal. Chem. 1995, 67(17), 3042-50. (E111) Jinno, K.; Yamamoto, K. J. Microcolumn Sep. 1992, 4(3), 18790. (E112) Ayrton, J.; Evans, M. B.; Harris, A. J.; Plumb, R. S. J. Chromatogr., B: Biomed. Appl. 1995, 667(1), 173-8. (E113) Wan, Q. H.; Shaw, P. N.; Davies, M. C.; Barrett, D. A. J. Chromatog., A 1995, 697(1+2), 219-27. (E114) Forgacs, E.; Cserhati, T. TrAC, Trends Anal. Chem. 1995, 14(1), 23-9. BIOPOLYMER SEPARATIONS (F1) Nawrocki, J.; Rigney, M. P.; McCormick, A.; Carr, P. W. J. Chromatogr., B: Biomed. Appl. 1993, 657, 292-82. (F2) Wirth, M. J.; Fatunmbi, H. O. LC-GC 1994, 12, 222-8. (F3) Schoneich, C.; Huhmer, A. F. R.; Rabel, S. R.; Stobaugh, J. F.; Jois, S. D. S.; Larive, C. K.; Siahaan, T. J.; Squier, T. C.; Bigelow, D. J.; Williams, T. D. Anal. Chem. 1995, 67, 155-81. (F4) Simpson, J. M. Bioprocess Technol. 1994, 18, 209-58. (F5) Gagnon, P.; Grund, E.; Lindbaek, T. LC-GC 1995, 13, 31828. (F6) Hicks, K. B. J. Chromatogr. Libr. 1995, 58, 361-87. (F7) Honda, S. J. Chromatogr. Libr. 1995, 58, 211-31. (F8) Nichols, R. NeuroProtocols 1994, 5, 104-10. (F9) Coupek, J.; Vins, I. J. Chromatogr., B: Biomed. Appl. 1994, 658, 391-8. (F10) Schott, H. Chromatogr. Sci. Ser. 1993, 63, 177-216. (F11) Levison, P. R. In Cellulosics; Velander, W. H., Kaster, J. A., Kumar, G., Cott, K. V., Oliviera, W. de, Glasser, W. G., Eds.; Horwood: Chichester, UK, 1993; pp 5-8. (F12) Kennedy, J. F.; Phillips, G. O.; Williams, P. A. In Cellulosics; Velander, W. H., Kaster, J. A., Kumar, G., Cott, K. V., Oliviera, W. de, Glasser, W. G., Eds.; Horwood: Chichester, UK, 1993; pp 25-36. (F13) Lorenzano-Porras, C. F.; Carr, P. W.; McCormick, A. V. J. Colloid Interface Sci. 1994, 164, 1-8. (F14) Lorenzano-Porras, C. F.; Annen, M. J.; Flickinger, M. C.; Carr, P. W., McCormick, A. V. J. Colloid Interface Sci. 1995, 170, 299-307. (F15) Sun, L.; Carr, P. W. Anal. Chem. 1995, 67, 3717-21. (F16) Itoh, H.; Nagae, N.; Kinoshita, T.; Nimura, N. Kuromatogurafi 1993, 14, 89R-98R. (F17) Yang, S.; Kruk, L. F. R.; Khaledi, M. G. J. Chromatogr., A 1994, 664, 1-11. (F18) Itoh, H.; Kinoshita, T.; Nimura, N. J. Chromatogr., A 1994, 662, 95-9. (F19) Queiroz, J. A.; Garcia, F. A.; Cabral, J. M. S. J. Chromatogr., A 1995, 707, 137-42. (F20) Agarwal, R.; Gupta, M. N. Anal. Chim. Acta 1995, 313, 2537. (F21) Yu, J.; El Rassi, Z. J. High Resolut. Chromatogr. 1994, 17, 7738. (F22) Wang, Q. C.; Svec, F.; Frechet, J. M. J. Anal. Chem. 1995, 67, 670-4. (F23) Horvath, J.; Boschetti, E.; Guerrier, L.; Cooke, N. J. Chromatogr., A 1994, 679, 11-22. (F24) Li, Y.-M.; Liao, J.-L.; Nakazato, K.; Mahammad, J.; Terenius, L.; Hjerten, S. Anal. Biochem. 1994, 223, 153-8. (F25) Ivanov, A. E.; Zubov, V. P. J. Chromatogr., B: Biomed. Appl. 1994, 673, 159-65. (F26) Da, S.-L.; Yue, W.-G.; Wen, Y.-F.; Da, H.-L.; Wang, Z.-H. Anal. Chim. Acta 1994, 299, 239-47. (F27) Ichimura, T.; Ikuta, N.; Uda, Y.; Horigome, T.; Omata, S. Anal. Biochem. 1995, 224, 250-5. (F28) Brekkan, L.; Lu, L.; Lundahl, P. J. Chromatogr., A 1995, 711, 33-42. (F29) Simms, P. J.; Haines, R. M.; Hicks, K. B. J. Chromatogr., B: Biomed. Appl. 1993, 648, 131-7. (F30) Inoue, S.; Ohtaki, N. J. Chromatogr., A 1994, 679, 247-53. (F31) Ge, H.; Gilmore, G.; Wallace, G. G. J. Liq. Chromatogr. 1994, 17, 1301-16. (F32) Fan, J.-Q.; Kondo, A.; Kato, I.; Lee, Y. C. Anal. Biochem. 1994, 219, 224-9. (F33) Montes, M. C.; van Amen, C.; Pesek, J. J.; Sandoval, J. E. J. Chromatogr., A 1994, 688, 31-45. (F34) Hatch, R. G. Chromatogr. Sci . 1993, 31, 469-73. (F35) Boyes, B. E.; Walker, D. G. J. Chromatogr., A 1995, 691, 33747. (F36) Yang, Y.; Velayundhan, A.; Ladisch, C. M.; Ladisch, M. R. Adv. Biochem. Eng./Biotechnol. 1993, 49, 147-60. (F37) Hjerten, S.; Nakazato, K.; Mohammad, J.; Eaker, D. Chromatographia 1993, 37, 287-94. (F38) Leonard, M.; Fournier, C.; Dellacherie, E. J. Chromatogr., B: Biomed. Appl. 1995, 664, 39-46. (F39) Lee, H. G.; Jarrett, H. W. J. Liq. Chromatogr. 1995, 18, 111322. 560R


(F40) Hosoya, K.; Kimata, K.; Araki, T.; Tanaka, N.; Frechet, J. M. J. Anal. Chem. 1995, 67, 1907-11. (F41) Hosoya, K.; Kishii, Y.; Kimata, K.; Araki, T.; Tanaka, N. Chromatographia 1994, 38, 177-82. (F42) Smigol, V.; Svec. F.; Frechet, J. M. J. Anal. Chem. 1994, 66, 2129-38. (F43) Smigol, V.; Svec, F.; Frechet, J. M. J. J. Liq. Chromatogr. 1994, 17, 259-76. (F44) Kataev, A. D.; Saburov, V. V.; Reznikova, O. A.; Kapustin, D. V.; Zubov, V. P. J. Chromatogr., A 1994, 660, 131-6. (F45) Freitag, R.; Frey, D.; Horvath, C. J. Chromatogr., A 1994, 686, 165-77. (F46) Kurganov, A.; Puchkova, Y.; Davankov, V.; Eisenbeiss, F. J. Chromatogr., A 1994, 663, 163-74. (F47) Rodrigues, A. E.; Loureiro, J. M.; Chenou, C.; Rendueles de la Vega, M. J. Chromatogr., B: Biomed. Appl. 1995, 664, 23340. (F48) Gerstner, J. A.; Morris, J.; Hunt, T. J. Chromatogr., A 1995, 695, 195-204. (F49) Brueggemann, B.; Schlueter, H.; Verspohl, E. J.; Zidek, W. FreseniusÅ J. Anal. Chem. 1994, 350, 719-21. (F50) Rogers, A. H.; Khaledi, M. G. Anal. Chem. 1994, 66 327-41. (F51) Furka, A.; Sebestyen, F.; Dibo, G. Pept. 1992, Proc. Eur. Pept. Symp., 22nd 1992, 463-4. (F52) Korakas, D.; Valko, K. J. Liq. Chromatogr. 1994, 17, 357184. (F53) Dass, C.; Mahalakshmi, P.; Grandberry, D. J. Chromatogr., A 1994, 678, 249-57. (F54) Ohguro, H.; Palczewski, K. FEBS Lett. 1995, 368, 452-4. (F55) Patthy, M. J. Chromatogr., A 1994, 660, 17-23. (F56) Contreras Martinez, S.; Vera-Avila, L. E. J. Chromatogr., A 1994, 667, 119-24. (F57) Huber, C. G.; Oefner, P. J.; Bonn, G. K. Anal. Chem. 1995, 67, 578-85. (F58) Swiderski, P. M.; Bertrand, E. L; Kaplan, B. E. Anal. Biochem. 1994, 216, 83-8. (F59) Pecina-Slaus, N.; Pavelic, J.; Pavelic, K. Period. Biol. 1994, 96, 161-4. (F60) Shimada, K.; Satoh, Y.; Nishimura, S. J. Liq. Chromatogr. 1995, 18, 713-23. (F61) Kopaciewicz, W.; Kellard, E.; Cox, G. B. J. Chromatogr., A 1995, 690, 9-19. (F62) Rippel, G.; Szepesy, L. J. Chromatogr., A 1994, 664, 27-32. (F63) Bollhagen, R.; Schmiedberger, M.; Grell, E. J. Chromatogr., A 1995, 711, 181-6. (F64) Boyes, B. E.; Kirkland, J. J. Pept. Res. 1993, 6, 249-58. (F65) Chen, H.; Horvath, C. J. Chromatogr., A 1995, 705, 3-20. (F66) Chen, H.; Horvath, C. Anal. Methods Instrum. 1993, 1, 21322. (F67) Huber, C. G.; Oefner, P. J.; Bonn, G. K. Chromatographia 1993, 37, 653-8. (F68) Chloupek, R. C.; Hancock, W. S.; Marchylo, B. A.; Kirkland, J. J.; Boyes, B. E.; Snyder, L. R. J. Chromatogr., A 1994, 686, 45-59. (F69) Hancock, W. S.; Chloupek, R. C.; Kirkland, J. J.; Snyder, L. R. J. Chromatogr., A 1994, 686, 31-43. (F70) Kwon, H.; Kim, J. Liq. Chromatogr. 1995, 18, 1437-49. (F71) Sereda, T. J.; Mant, C. T.; Hodges, R. S. J. Chromatogr., A 1995, 695, 205-21. (F72) Aguilar, M. I.; Mougos, S.; Boublik, J.; Rivier, J.; Hearn, M. T. W. J. Chromatogr., B: Biomed. Appl. 1993, 646, 53-65. (F73) Tamaki, M.; Akabori, S.; Muramatsu, I. J. Chromatogr., A 1994, 685, 237-41. (F74) Friebe, S.; Hartrodt, B.; Neubert, K.; Krauss, G.-J. J. Chromatogr., A 1994, 661, 7-12. (F75) Hodges, R. S.; Zhu, B.-Y.; Zhou, N. E.; Mant, C. T. J. Chromatogr., A 1994, 676, 3-15. (F76) de Collongue-Poyet, B.; Vidal-Madjar, C.; Sebille, B.; Inger, K. K. J. Chromatogr., B: Biomed. Appl. 1995, 664, 155-61. (F77) Hanson, M.; Unger, K. K.; Denoyel, R.; Rouguerol, J. J. Biochem. Biophys. Methods 1994, 29, 283-93. (F78) Anita, F. D.; Fellegvari, I.; Horvath, C. Ind. Eng. Chem. Res. 1995, 34, 2796-804. (F79) Feng, W.; Jiang, X.; Geng, X. J. Liq. Chromatogr. 1995, 18, 217-26. (F80) Corradini, D.; Capitani, D.; Cellai, L. J. Liq. Chromatogr. 1994, 17, 4334-47. (F81) Oscarsson, S. J. Chromatogr., B: Biomed. Appl. 1995, 666, 21-31. (F82) Lee, D. W.; Cho, B. Y. J. Liq. Chromatogr. 1994, 17, 254158. (F83) Szepesy, L.; Rippel, G. J. Chromatogr., A 1994, 668, 337-44. (F84) Jenoe, P.; Scherer, P. E.; Manning-Krieg, U.; Horst, M. Anal. Biochem. 1993, 215, 292-8. (F85) Alpert, A. J.; Shukla, M.; Shukla, A. K.; Zieske, L. R.; Yuen, S. W.; Ferguson, M. A. J., Mehlert, A.; Pauly, M.; Orlando, R. J. Chromatogr., A 1994, 676, 191-202. (F86) Heng, M. H.; Glatz, C. E. J. Chromatogr., A 1995, 689, 22734. (F87) Li, Y.; Pinto, N. G. J. Chromatogr., A 1995, 702, 113-23. (F88) Luo, R. G.; Hsu, J. T. Sep. Technol. 1993, 3, 221-9. (F89) Lu, T.; Gray, H. B., Jr. J. Chromatogr., A 1994, 686, 339-43. (F90) Mhatre, R.; Nashabeh, W.; Schmalzing, D.; Yao, X.; Fuchs, M.; Whitney, D.; Regnier, F. J. Chromatogr., A 1995, 707, 22531.

(F91) Ausserer, W. A.; Biros, M. L. BioTechniques 1995, 19, 1369. (F92) Sumita, C.; Baba, Y.; Hide, K.; Ishimara, N.; Samata, K.; Tanaka, A.; Tsuhako, M. J. Chromatogr., A 1994, 661, 297-303. (F93) Corradini, C.; Corradini, D.; Huber, C. G.; Bonn, G. K. J. Chromatogr., A 1994, 685, 213-20. (F94) Frenz, J.; Qaun, C. P.; Cacia, J.; Democko, C.; Bridenbaugh, R.; McNerney, T. Anal. Chem. 1994, 66, 335-40. (F95) Cheng, L.; Kindel, P. K. Anal. Biochem. 1995, 228, 109-14. (F96) Jayaraman, G.; Li, Y.-F.; Moore, J. A.; Cramer, S. M. J. Chromatogr., A 1995, 702, 143-55. (F97) Patrickios, C. S.; Gadam, S. D.; Cramer, S. M.; Hertler, W. R.; Hotton, T. A. Biotechnol. Prog. 1995, 11, 33-8. (F98) Kunda, A.; Vunnum, S.; Cramer, S. M. J. Chromatogr., A 1995, 707, 57-67. (F99) Gadam, S. D.; Cramer, S. M. Chromatographia 1994, 39, 40918. (F100) Xie, J.; Aguilar, M.-I.; Hearn, M. T. W. J. Chromatogr., A 1995, 711, 43-52. (F101) Sabharwal, A. P.; Chase, H. A. IChemE Res. Event, Two-Day Symp. 1994, 1, 265-7. (F102) Jungbauer, A.; Hackl, S.; Yamamoto, S. J. Chromatogr., B: Biomed. Appl. 1994, 658, 399-406. (F103) Gallant, S. R.; Kundu, A.; Cramer, S. M. Biotechnol. Bioeng. 1995, 47, 355-72. (F104) Yamamoto, S.; Suehisa, T.; Tomoyuki, S. Y. Chem. Eng. Commun. 1993, 119, 221-30. (F105) Cartier, P. G.; Maikner, J. J.; Diessler, K. C.; Fisher, J. R. Pept.: Chem., Struct. Biol., Proc. Am. Pept. Symp., 13th 1993, 232-4. (F106) Wu, D.-R.; Greenblatt, H. C. J. Chromatogr., A 1995, 702, 15762. (F107) Cartier, P. G.; Deissler, K. C.; Maikner, J. J.; Kraus, M. Spec. Publ.-R. Soc. Chem. 1994, 158, 100-5. (F108) Gerstner, J. A.; Pedroso, P.; Morris, J.; Bergot, B. J. Nucleic Acids Res. 1995, 23, 2292-9. (F109) Svec, F.; Frechet, J. M. J. J. Chromatogr., A 1995, 702, 8995. (F110) Velayudhan, A.; Horvath, C. J. Chromatogr., A 1994, 663, 1-10. AFFINITY CHROMATOGRAPHY (G1) (G2) (G3) (G4) (G5) (G6) (G7) (G8) (G9) (G10) (G11) (G12) (G13) (G14) (G15) (G16) (G17) (G18) (G19) (G20) (G21) (G22) (G23) (G24) (G25) (G26) (G27) (G28) (G29) (G30) (G31) (G32)

Deshpande, S. S. IFT Basic Symp. Ser. 1995, 10, 297-332. Villems, R.; Toomik, P. Chromatogr. Sci. Ser. 1993, 63, 3-60. Pepper, D. S. Mol. Biotechnol. 1994, 2, 157-78. Larsson, P. O. Chromatogr. Sci. Ser. 1993, 63, 61-75. Winzor, D. J.; Jackson, C. M. Chromatogr. Sci. Ser. 1993, 63, 253-98. Cameron, G. W. W.; Bruce, N. C. Methods Mol. Cell Biol. 1993, 4, 184-8. Harakas, N. K. Bioprocess Technol. 1994, 18, 259-316. Page, M. G. P. Chromatogr. Sci. Ser. 1993, 63, 143-60. Friedberg, F.; Rhoads, A. R. Chromatogr. Sci. Ser. 1993, 63, 79-109. Narayanan, S. R. J. Chromatogr. 1994, 658, 237-58. Farooqui, A. A.; Yang, H.; Horrocks, L. A. J. Chromatogr., A 1994, 658, 237-58. Moncollin, V. Egly, J. M. Chromatogr. Sci. Ser. 1993, 63, 16175. Honda, S. J. Chromatogr. Libr. 1995, 58, 211-31. Mattiasson, B.; Linne, E.; Kaul, R. Mol. Interact. Biosep. 1993, 395-401. Chaiken, I. Mol. Interact. Biosep. 1993, 169-77. Schott, H. Chromatogr. Sci. Ser. 1993, 63, 177-216. Uhlen, M,; Olsvik, O.; Hornes, E. Mol. Interact. Biosep. 1993, 479-85. Yip, T. T.; Hutchens, T. W. Mol. Biotechnol. 1994, 1, 15164. Jack, G. W. Mol. Biotechnol. 1994, 1, 59-86. Hill, C. R. In Monoclonal Antibodies Principles and Applications; Birch, J. R., Lennox, E. S., Eds.; Wiley: New York, 1995; pp 193-214. Sridhar, P.; Sastri, N. S. V. Indian Chem. Eng. 1994, 36, 728. Sridhar, P.; Sastri, N. V. S.; Modak, J. M.; Mukherjee, A. K. Chem. Eng. Technol. 1994, 17, 422-9. Carlsson, F.; Axelsson, A.; Zacchi, G. Comput. Chem. Eng. 1993, 18, S657-61. Chen, W. Y.; Lui, P. K.; Wang, L. K.; Wu, C. F.; Lin, R. Y. J. Chin. Inst. Chem. Eng. 1995, 26, 19-25. Kim, Y. J. Biotechnol. Tech. 1995, 9, 623-8. Vunnum, S.; Gallant, S. R.; Kim, Y. J.; Cramer, S. M. Chem. Eng. Sci. 1995, 50, 1785-803. Kim, D.-H.; Garcia, A. A.; Biotechnol. Prog. 1995, 11, 465-7. Glavanovich, M. H.; Carr, P. W. Anal. Chem. 1994, 66, 25849. Petrescu, S.; Branza-Nichita, N.; Nita-Lazar, M.; Petrescu, A.J.; Motas, C. Anal. Biochem. 1995, 229, 299-303. Li, Q.; Zhu, J.; Daugulis, A. J.; Hsu, C. C.; Goosen, M. F. A. Biomater., Artif. Cells, Immobilization Biotechnol. 1993, 21, 391-8. Inomata, Y.; Wada, T.; Handa, H.; Fujimoto, K.; Kawaguchi, H. Proc. Int. Conf. Intell. Mater. 1993, 1, 442-5. Gebben, B. van Houwelingen, G. D. B.; Zhang, W.; van den Boomgaard, T. Colloids Surf., B 1994, 3, 75-84.

(G33) Galaev, I. Y.; Mattiasson, B. J. Chromatogr., A 1994, 662, 2735. (G34) Zusman, R.; Zusman, I. Biotechnol. Appl. Biochem. 1995, 21, 161-72. (G35) Lakhiari, H.; Muller, D.; Jozefonicz, J. J. Chromatogr., A 1995, 711, 93-103. (G36) Lakhiari, H.; Legendre, E.; Muller, D.; Jozefonvicz, J. J. Chromatogr., B: Biomed. Appl. 1995, 664, 163-73. (G37) Westmark, P. R.; Valencia, L. S.; Smith, B. D. J. Chromatogr., A 1994, 664, 123-8. (G38) Galeev, I. Y.; Arvidsson, P.; Mattiasson, B. J. Chromatogr., A 1995, 710, 259-66. (G39) Galeev, I. Y.; Warrol, C.; Mattiasson, B. J. Chromatogr., A 1994, 684, 37-43. (G40) Wheatley, J. B.; Kelley, M. K.; Montali, J. A.; Berry, C. O. A.; Schmidt, D. E., Jr. J. Chromatogr., A 1994, 663, 53-63. (G41) Burton, N. P.; Lowe, C. R. J. Mol. Recognit. 1993, 6, 31-40. (G42) Ticha, M.; Zelezna, B.; Jonakova, V.; Filka, K. J. Chromatogr., B: Biomed. Appl. 1994, 656, 423-6. (G43) Calvete, J. J.; Reinert, M.; Sanz, L.; Toepfer-Petersen, E. J. Chromatogr., A 1995, 711, 167-73. (G44) Alvarez, C.; Bertorello, H.; Strumia, M. J. Appl. Polym. Sci. 1994, 54, 1887-91. (G45) Schwarz, A.; Kohen, F.; Wilchek, M. React. Polym. 1994, 22, 259-66. (G46) Yoshihara, Y.; Kuroda, M. J. Biochem. 1995, 117, 443-6. (G47) Bottomley, S. P.; Sutton, B. J.; Gore, M. G. J. Immunol. Methods 1995, 182, 185-92. (G48) Luo, J.; Wolfe, B. B. BioTechnoques 1995, 19, 544-50. (G49) Verdoliva, A.; Cassani, G.; Fassina, G. J. Chromatogr., B: Biomed. Appl. 1995, 664, 175-83. (G50) Kang, S.-H.; Xu, X.; Heidenreich, O.; Gryanzov, S.; Nerenberg, M. Nucleic Acids Res. 1995, 23, 2344-5. (G51) Langland, J. O.; Pettiford, S. M.; Jacobs, B. L. Protein Expression Purif. 1995, 6, 25-32. (G52) DiRusso, C.; Rogers, R. P.; Jarrett, H. W. J. Chromatogr., A 1994, 677, 45-52. (G53) Edery, I.; Chu, L. L.; Soneberg, N.; Pelletier, J. Mol. Cell. Biol. 1995, 15, 3363-71. (G54) Lorenz, B.; Marme, S.; Mueller, W. E. G.; Unger, K.; Schroeder, H. C. Anal. Biochem. 1994, 216, 118-26. (G55) Johnson, P. R.; Stern, N. J.; Eitman, P. D.; Rasmussen, J. K.; Milbrath, D. S.; Gleason, R. M.; Hogancamp, R. E. J. Chromatogr., A 1994, 667, 1-9. (G56) Huang, P. Y.; Carbonell, R. G. Biotechnol. Bioeng. 1995, 47, 288-97. (G57) Subramanian, A.; Van Cott, K. E.; Milbrath, D. S.; Velander, W. H. J. Chromatogr., A 1994, 672, 11-24. (G58) Todd, R. J.; Johnson, R. D.; Arnold, F. H. J. Chromatogr., A 1994, 662, 13-26. (G59) Boden, V.; Winzerling, J. J.; Vijayalakshmi, M.; Porath, J. J. Immunol. Methods 1995, 181, 225-32. (G60) Flurer, C. L.; Novotny, M. J. Microcolumn Sep. 1993, 4, 497501. (G61) Hansen, P.; Lindberg, G. J. Chromatogr., A 1994, 662, 23541. (G62) Hansen, P.; Lindberg, G. J. Chromatogr., A 1995, 690, 1559. (G63) Anspach, F. B. J. Chromatogr., A 1994, 672, 35-49. (G64) Anspach, F. B. J. Chromatogr., A 1994, 676, 249-66. (G65) Anspach, F. B.; Altmann-Haase, G. Biotechnol. Appl. Biochem. 1994, 20, 323-33. (G66) Miles, D.; Garcia, A. A. J. Chromatogr., A 1995, 702, 17389. (G67) Garcia, A. A.; Kim, D. H.; Miles, D. R. React. Polym. 1994, 23, 249-59. ION CHROMATOGRAPHY (H1) Weiss, J. Ion Chromatography, 2nd ed.; VCH: Weinheim, Germany, 1994. (H2) Timerbaev, A. R.; Bonn, G. K. J. Chromatogr. 1993, 640(12), 195-206. (H3) Janos, P. J. Chromatogr., A 1995, 699(1+2), 1-10. (H4) Hoffman, N. E. Adv. Chromatogr. (N.Y.) 1994, 34, 309-46. (H5) Rowland, A. P.; Woods, C.; Kennedy, V. H. J. Chromatogr., A 1995, 706(1+2), 229-39. (H6) Tartari, G. A.; Marchetto, A.; Mosello, R. J. Chromatogr., A 1995, 706(1+2), 21-9. (H7) Marchetto, A.; Mosello, R.; Tartari, G. A.; Muntau, H.; Bianchi, M.; Geiss, H.; Serrini, G.; Serrini, L.; Gianna J. Chromatogr., A 1995, 706(1+2), 13-9. (H8) Edgell, K. W.; Longbottom, J. E.; Pfaff, J. D. J. ADAC Int. 1994, 77(5), 1253-63. (H9) Simpson, M. R.; Macleod, B. W. Proc.-Water Qual. Technol. Conf. 1993, (PT.2), 1167-82. (H10) Jackson, P. E.; Romano, J. P.; Wildman, B. J. J. Chromatogr., A 1995, 706(1+2), 3-12. (H11) Kreling, J. R.; Cowan, J. S.; Block, F.; DeZwaan, J. J. Chromatogr., A 1994, 671(1-2), 295-302. (H12) Thienpont, Linda M.; Van Nuwenborg, J. E.; Stoecki, D. J. Chromatogr., A 1995, 706(1-2), 443-50. (H13) Papoff, P.; Ceccarini, A.; Carnevali, P. J. Chromatogr., A 1995, 706(1+2), 43-54. (H14) Von Helden, G.; Wyttenbach, T.; Bowers, M. T. Science (Washington, D.C.) 1995, 267(5203), 1483-5.


561R

(H15) Lee, S.; Gotts, N. G.; von Helden, G.; Bowere, M. T. Science (Washington, D.C.) 1995, 267(5200), 999-1001. (H16) Strout, D. L.; Book. L. D.; Millam, J. M.; Xu, C.; Scuseria, G. E. J. Phys. Chem. 1994, 98(35), 8622-6. (H17) Gros, N.; Gorenc, B. J. Chromatogr., A 1995, 697(1+2), 3143. (H18) Jenke, D. R. Anal. Chem. 1994, 66(24), 4466-70. (H19) Hjos, P.; Horvath, O.; Dende, V. Anal. Chem. 1995, 67(2), 434-41. (H20) Mongay, C.; Olmos, C.; Pastor, A. J. Chromatogr., A 1994, 683(2), 355-65. (H21) Staahlberg, J. Anal. Chem. 1994, 66(4), 440-9. (H22) Foti, G.; Hajos, P.; Kovats, E. Talanta 1994, 41, 1073-81. (H23) Zappoli, S.; Bottura, C. Anal. Chem. 1994, 66(20), 3492-9. (H24) Hajos, P.; Revesz, G.; Sarzanni, C.; Sacchero, G.; Mentasti, E. J. Chromatogr. 1993, 640(1-2), 15-25. (H25) Dumont, P. J.; Fritz, J. S.; Schmidt, L. W. J. Chromatogr., A 1995, 706(1+2), 109-14. (H26) Dumont, P. J.; Frita, J. S. J. Chromatogr., A 1995, 706(1+2), 149-58. (H27) Croes, K.; McCarthy, P. T.; Flanagan, R. J. J. Chromatogr., A 1995, 693(2), 289-306. (H28) Kingery, A. F.; Allen, H. E. Anal. Chem. 1994, 66(1), 155-9. (H29) Nishimura, M.; Hayashi, M.; Yamamoto, A.; Horikawa, T.; Hayakawa, K.; Miyazaki, M. J. Chromatogr., A 1995, 708(2), 195-201. (H30) Shibukawa, M. J. Chromatogr. 1993, 655(2), 199-205. (H31) Shamsi, S. A.; Danielson, N. D. J. Chromatogr. 1993, 653(1), 153-60. (H32) Hirayama, N.; Maruo, M.; Shiota, A.; Kuwamoto, T. J. Chromatogr., A 995, 707(2), 384-9. (H33) Laeubli, M. W.; Kampus, B. J. Chromatogr., A 1995, 706(1+2), 103-7. (H34) Villasenor, S. R. J. Chromatogr., A 1994, 671(1-2), 11-4. (H35) Kumagai, H.; Sakai, T.; Matsumoto, K.; Hanaoka, Y. J. Chromatogr., A 1994, 671(1-2), 15-22. (H36) Umile, C.; Huber, J. F. K. Talanta 1994, 41(7), 1101-6. (H37) Sellergren, B.; Shea, K. J. J. Chromatogr. 1993, 654(1), 1728. (H38) Eleveld, J. T.; Claessens, H. A.; Ammerdorffer, J. L.; van Herk, A. M.; Cramers, C. A. J. Chromatogr., A 1994, 677(2), 21127. (H39) Walshe, M.; Kelly, M. T.; Smyth, M. R.; Ritchie, H. J. Chromatogr., A 1995, 708(1), 31-40. (H40) Hu, W.; Haraguchi, Hl Anal. Chem. 1994, 66(5), 765-77. (H41) Hu, W.; Tao, H.; Tominaga, M; Miyazaki, A.; Haraguchi, H. Anal. Chim. Acta 1994, 299(2), 249-56. (H42) Hu, W.; Haraguchi, H. Anal. Chim. Acta 1994, 285(3), 33541. (H43) Nesterenko, P. N.; Elefterov, A. I.; Tarasenko, D. A.; Shpigun, O. A. J. Chromatogr., A 1995, 706(1+2), 59-68. (H44) Ding, M.-Y.; Suzuki, Y.; Koizumi, H. Chromatographia 1995, 40(9/10), 539-44. (H45) Ding, M.-Y.; Suzuki, Y.; Koizumi, H. Analyst (Cambridge, U.K.) 1995, 120(6), 1773-7. (H46) McNeff, C.; Zhao, Q.; Carr, P. W. J. Chromatogr., A 1994, 684(2), 201-12. (H47) McNeff, C.; Carr, P. W. Anal. Chem. 1995, 67(21), 3866-92. (H48) Yu, J.; El Rassi, Z. J. High Resolut. Chromatogr. 1994, 17(10), 705-12. (H49) ÅInoue, Y.; Tani, K.; Suzuki, Y. Chromatographia 1995, 40(9/ 10), 577-80. (H50) Biernat, J. F.; Konieczka, P.; Tarbet, B. J.; Bradshaw, J. S.; Izatt, R. M. Sep. Purif. Methods 1994, 23(2), 77-348. (H51) Lamb, J. D.; Smith, R. G.; Anderson, R. C.; Mortensen, M. K. J. Chromatogr., A 1994, 671(1-2), 55-62. (H52) Edwards, B. R.; Giauque, A. P.; Lamb, J. D. J. Chromatogr., A 1995, 706(1+2), 69-79. (H53) Nair, L. M.; Saari-Nordhaus, R.; Anderson, J. M., Jr. J. Chromatogr., A 1994, 671(1-2), 43-9. (H54) Laeubli, M. W.; Kampus, B. J. Chromatogr., A 1995, 706(1+2), 99-102. (H55) Krokhin, O. V.; Smolenkov, A. D.; Obrezkov, O. N.; Shpigun, O. A. J. Chromatogr., A 1995, 706(1+2), 93-8. (H56) Danielson, N. D.; Wangsa, J.; Shamsi, S. A. J. Liq. Chromatogr. 1995, 18(13), 2579-92. (H57) Huhn, G.; Mueller, H. J. Chromatogr. 1993, 640(1-2), 5764. (H58) Ryan, N.; Glennon, J. D.; Muller, D. Anal. Chim. Acta 1993, 283(1), 344-9. (H59) Lee, H. G.; Jarrett, H. W. J. Liq. Chromatogr. 1995, 18(6), 113-22. (H60) Sjoegren, A.; Dasgupta, P. K. Anal. Chem. 1995, 67(13), 2110-18l (H61) Klingenberg, A.; Seubert, A. J. Chromatogr. 1993, 640(1-2), 167-78. (H62) Dolgonosov, A. M. J. Chromatogr. 1994, 67(1-2), 330-41. (H63) Nagaoka, T.; Nakao, N.; Tabusa, K.; Yano, J.; Ogura, K. J. Electroanal. Chem. 1994, 37(1-2), 283-6. (H64) Rabin, S.; Stillian, J.; Barreto, V.; Friedman, K.; Toofan, M. J. Chromatogr. 1993, 640(1-2), 97-109. (H65) Watanabe, H.; Sato, H. J. Chromatogr., A 1995, 706(1+2), 55-7. (H66) Zuo, X. J.; Chen, L. R.; Wang, Q. Chromatographia 1994, 39(11/12), 713-8. 562R


(H67) Kaljurand, M.; Urbas, E.; Haldna, U. J. Chromatogr. 1994, 660(1-2), 147-52. (H68) Sato, H.; Dasgupta, P. K. Anal. Chim. Acta 1993, 284(1), 2736. SECONDARY CHEMICAL EQUILIBRIA (I1) Marriott, P. J.; Lai, Y.-H. Chem. Aust. 1994, 61, 386-9. (I2) Ward, T. J.; Ward, K. D. Surfactant Sci. Ser. 1995, 55, 51740. (I3) van Beek, T. a.; Subrtova, D. Phytochem. Anal. 1995, 6, 1-19. (I4) Schoenmakers, P. J.; Tijssen, R. J. Chromatogr. 1993, 656, 577-90. (I5) Chen, J.-G.; Weber, S. G.; Glavina, L. L.; Cantwell, F. F. J. Chromatogr. 1993, 656, 549-76. (I6) Bieganowska, M. L.; Petruczynik, A. Chem. Anal. 1994, 39(5), 525-41. (I7) Gennaro, M. C. Adv. Chromatogr. 1995, 35, 343-81. (I8) Zou, H.-F.; Zhang, Y.-K.; Hong, M.-F.; Lu, P.-C. Prog. Nat. Sci. 1994, 4, 398-406. (I9) Yang, S.; Kruk, L. F. R.; Khaledi, M. G. J. Chromatogr., A 1994, 664, 1-11. (I10) Yang, S.; Khaledi, M. G. Anal. Chim. Acta 1994, 294, 13543. (I11) Madamba-Tan, L. S.; Strasters, J. K.; Khaledi, M. G. J. Chromatogr., A 1994, 683, 321-34. (I12) Madamba-Tan, L. S.; Strasters, J. K.; Khaledi, M. G. J. Chromatogr., A 1994, 683, 335-45. (I13) Zou, H.; Zhang, Y.; Lu, P. Anal. Chim. Acta 1995, 310, 46171. (I14) Funasaki, N.; Hada, S.; Neya, S. Bull. Chem. Soc. Jpn. 1994, 67, 65-73. (I15) Pinto, C. G.; Perez, J. L.; Cordero, B. M. Analyst 1995, 120(1), 53-62. (I16) Zibas, S. A.; Cline Love, L. J. Anal. Chim. Acta 1994, 299, 1727. (I17) Rodriguez Delgado, M. A.; Sanchez, M. J.; Gonzalez, V.; Garcia Montelongo, F. Anal. Chim. Acta 1994, 298, 423-30. (I18) Rodriguez Delgado, M. A.; Sanchez, M. J.; Gonzalez, V.; Garcia Montelongo, F. J. Chromatogr., A 1995, 697, 71-80. (I19) Rodriguez, M. A.; Sanchez, M. J.; Gonzalez, V.; Montelongo, G. Chromatographia 1994, 38, 342-8. (I20) Saz, J. M.; Marina, M. L. J. Chromatogr., A 1994, 687, 1-12. (I21) Zhang, Y.; El Rassi, Z. J. Liq. Chromatogr. 1995, 18, 3373-96. (I22) Haupt, D.; Pettersson, C.; Westerlund, D. Chirality 1993, 5, 224-8. (I23) Haupt, D.; Pettersson, C.; Westerlund, D. Chirality 1995, 7, 23-7. (I24) Lavine, B. K.; Cooper, W. T., III; He, Y.; Hendayana, S.; Han, J. H.; Tetreault, J. J. Colloid Interface Sci. 1994, 165, 497-504. (I25) Lavine, B. K.; Hendayana, S.; Tetreault, J. Anal. Chem. 1994, 66, 3458-65. (I26) Bonet-Domingo, E.; Medina-Hernandez, M. J.; Garcia-AlvarezCoque, M. C. Quim. Anal. 1993, 12(4), 167-72. (I27) Torres-Lapasio, J. R.; Villanueva-Camanas, R. M.; SanchisMallols, J. M.; Medina-Hernandez, M. J.; Garcia-Alvarez-Coque, M. C. J. Chromatogr., A 1994, 677, 239-53. (I28) Garcia, M. A.; Jimenez, O.; Marina, M. L. J. Chromatogr., A 1994, 675, 1-11. (I29) Lopez-Lopez, D.; Rubio-Barroso, S.; Polo-Diez, L. M. J. Liq. Chromatogr. 1995, 18, 2397-425. (I30) Garrone, A.; Fornatto, E.; Marengo, E.; Gasco, A. Ann. Chim. 1993, 83(11-12), 499-510. (I31) Marina, M. L.; Garcia, M. A.; Pastor, M.; Vera, S. Chromatographia 1995, 40, 185-92. (I32) Nakamura, K.; Hayashi, K.; Ueda, I.; Fujiwara, H. Chem. Pharm. Bull. 1995, 43, 369-73. (I33) Tanaka, A.; Nakamura, K.; Nakanishi, I.; Fujiwara, H. J. Med. Chem. 1994, 37, 4563-6. (I34) Sanchis Mallols, J. M.; Torres Lapasio, J. R.; Villanueva Camanas, R. M.; Ramis-Ramos, G. Chromatographia 1994, 39, 591-6. (I35) Sanchis Mallols, J. M.; Villanueva Camanas, R. M.; RamisRamos, G. Chromatographia 1994, 38, 365-72. (I36) Loevgren, U.; Johansson, M.; Kronkvist, K.; Edholm, L.-E. J. Chromatogr., B: Biomed. Appl. 1995, 672, 33-44. (I37) Catala-Icardo, M.; Medina-Hernandez, M. J.; Garcia AlvarezCoque, M. C. J. Liq. Chromatogr. 1995, 18, 2827-41. (I38) Strege, M. A.; Lagu, A. L. J. Chromatogr., A 1995, 705, 15561. (I39) Garcia-Alvarez-Coque, M. C.; Simo-Alfonso, E. F.; Ramis-Ramos, G.; Esteve-Romero, J. S. J. Pharm. Biomed. Anal. 1995, 13, 237-45. (I40) Villanueva Camanas, R. M.; Sanchis Mallols, J. M.; Torres Lapasio, J. R.; Ramis-Ramos, G. Analyst 1995, 120(6), 176772. (I41) Ding, H.; Wang, J.; Dorsey, J. G.; Caruso, J. A. J. Chromatogr., A 1995, 694, 425-31. (I42) Inoue, Y.; Kawabata, K.; Suzuki, Y. J. Anal. At. Spectrom. 1995, 10, 363-6. (I43) Hadjmohammadi, M. R.; Fatemi, M. H. J. Liq. Chromatogr. 1995, 18, 2569-78. (I44) Peng, W.; Li, T.; Li, H.; Wang, E. Anal. Chim. Acta 1994, 298, 415-21. (I45) Carretero, I.; Vadillo, J. M.; Laserna, J. J. Analyst 1995, 120(6), 1729-32.

(I46) Lin, M.; Wu, N.; Aiken, J. H. J. Liq. Chromatogr. 1995, 18, 1219-29. (I47) Perez-Martinez, I.; Sagrado, S.; Medina-Hernandez, M. J. Anal. Chim. Acta 1995, 304, 195-201. (I48) Simo-Alfonso, E. F.; Ramis-Ramos, G.; Garcia-Alvarez-Coque, M. C.; Esteve-Romero, J. S. J. Chromatogr., B: Biomed. Appl. 1995, 670, 183-7. (I49) Vadillo, J. M.; Gonzalez, M. E.; Carretero, I.; Laserna, J. J. Mikrochim. Acta 1995, 118, 273-82. (I50) Yang, S.; Khaledi, M. G. J. Chromatogr., A 1995, 692, 311-8. (I51) Barbosa, J.; Berges, R.; Sanz-Nebot, V. J. Liq. Chromatogr. 1995, 18, 3445-63. (I52) Kirkland, J. J.; van Straten, M. A.; Claessens, H. A. J. Chromatogr., A 1995, 691, 3-19. (I53) Uhl, S.; Rempfer, K.; Egelhaaf, H. J.; Lehr, B.; Oelkrug, D. Anal. Chim. Acta 1995, 303, 17-23. (I54) Nagaoka, T.; Kakuno, K.; Fujimoto, M.; Nakao, H.; Yano, J.; Ogura, K. J. Electroanal. Chem. 1994, 368, 315-7. (I55) Ito, Y.; Ma, Y. J. Chromatogr., A 1994, 672, 101-8. (I56) Denekamp, C.; Mandelbaum, A.; Weisz, A.; Ito, Y. J. Chromatogr., A 1994, 685, 253-7. (I57) Ma, Y.; Ito, Y. J. Chromatogr., A 1994, 678, 233-40. (I58) Ma, Y.; Ito, Y.; Sokolosky, E.; Fales, H. M. J. Chromatogr., A 1994, 685, 259-62. (I59) Ma, Y.; Ito, Y. J. Chromatogr., A 1995, 702, 197-206. (I60) Hendriks, M. M. W. B.; Coenegracht, P. M. J.; Doornbos, D. A. Chemom. Intell. Lab. Syst. 1994, 25, 227-39. (I61) Gennaro, M. C.; Abrigo, C.; Marengo, E. J. Liq. Chromatogr. 1994, 17, 1231-44. (I62) Gennaro, M. C.; Giacosa, D.; Abrigo, C. J. Liq. Chromatogr. 1994, 17, 4365-80. (I63) Nivaud-Guernet, E.; Guernet, M.; Ivanovic, D.; Medenica, M. J. Liq. Chromatogr. 1994, 17, 2343-57. (I64) Ivanovic, D.; Medenica, M.; Nivaud-Guernet, E.; Guernet, M. Chromatographia 1995, 40, 652-6. (I65) Uno, B.; Okumura, N.; Kawai, S. Bull. Chem. Soc. Jpn. 1994, 67, 3356-9. (I66) Li, L. Y.; Gui, M.-D.; Zhao, Y.-Q. Talanta 1995, 42, 89-92. (I67) Shoupu, L.; Mingqiao, Z.; Chuanyue, D. Talanta 1994, 41, 279-82. (I68) Stalberg, O.; Arvidsson, T. J. Chromatogr., A 1994, 684, 2139. (I69) Stefansson, M.; Westerlund, D. J. Chromatogr. Sci. 1994, 32, 46-9. (I70) Okada, T.; Usui, T. J. Chromatogr., A 1994, 676, 355-9. (I71) Kurganov, A.; Davankov, V.; Unger, K.; Eisenbeiss, F.; Kinkel, J. J. Chromatogr., A 1994, 666, 99-110. (I72) Nair, L. M.; Saari-Nordhaus, R.; Anderson, J. M., Jr. J. Chromatogr., A 1994, 671, 43-9. (I73) Rozbeh, M.; Hurtubise, R. J. J. Liq. Chromatogr. 1995, 18, 1737. (I74) Rozbeh, M.; Hurtubise, R. J. J. Liq. Chromatogr. 1995, 18, 1909-31. (I75) Husain, N.; Christian, A. Y.; Warner, I. M. J. Chromatogr., A 1995, 699, 73-83. (I76) Lamparczyk, H.; Zarzycki, P. K. J. Pharm. Biomed. Anal. 1995, 13, 543-9. (I77) Nowakowski, R.; Cardot, P. J. P.; Coleman, A. W.; Villard, E.; Guiochon, G. Anal. Chem. 1995, 67, 259-66. (I78) Letellier, S.; Maupas, B.; Guyon, F. Pharm. Acta Helv. 1994, 68, 229-33. (I79) Shimada, K.; Satoh, Y.; Nishimura, S. J. Liq. Chromatogr. 1995, 18, 713-23. (I80) Shimada, K.; Nishimura, S. J. Liq. Chromatogr. 1995, 18, 1691701. (I81) Shimada, K.; Mitamura, K.; Kaji, H.; Morita, M. J. Chromatogr. Sci. 1994, 32, 107-11. (I82) Shimada, K.; Mitamura, K.; Miura, M.; Miyamoto, A. J. Liq. Chromatogr. 1995, 18, 2885-93. (I83) Letellier, S.; Maupas, B.; Gramond, J. P.; Guyon, F.; Gareil, P. Anal. Chim. Acta 1995, 315, 357-63. (I84) Zou, H.; Zhang, Y.; Hong, M.; Lu, P. Prog. Nat. Sci. 1995, 5, 106-12. (I85) Klyushnichenko, V. E.; Yakimov, S. A.; Arutyunyan, A. M.; Ivanov, A. E.; Maltsev, K. V.; Wulfson, A. N. J. Chromatogr., B: Biomed. Appl. 1994, 662, 363-9. (I86) Patthy, M. J. Chromatogr., A 1994, 660, 17-23. (I87) Goosens, E. C.; Beerthuizen, I. M.; de Jong, D.; de Jong, G. J.; Brinkman, U. A. T. Chromatographia 1995, 40, 267-71. (I88) Jandera, P.; Urbanek, J. J. Chromatogr., A 1995, 689, 255-67. (I89) Harfst, S.; Moller, D.; Ketz, H.; Roesler, J.; Gabel, D. J. Chromatogr., A 1994, 678, 41-8. (I90) Huber, C. G.; Oefner, P. J.; Bonn, G. K. Anal. Chem. 1995, 67, 578-85. (I91) Varga-Defterdarovic, L.; Horvat, S.; Skuric, M.; Horvat, J. J. Chromatogr., A 1994, 687, 101-6. (I92) Chuang, C. Z.; Ragan, F. A., Jr.; Prasad, C. J. Liq. Chromatogr. 1994, 17, 2383-94. (I93) Dass, C.; Mahalakshmi, P.; Grandberry, D. J. Chromatogr., A 1994, 678, 249-57. (I94) McCrossen, S. D.; Simpson, C. F. Anal. Proc. 1994, 31, 9-11. (I95) Zou, H.; Zhang, Y.; Hong, M.; Lu, P. J. Liq. Chromatogr. 1994, 17, 707-19. (I96) Bieganowska, M. L.; Petruczynik, A. Chromatographia 1995, 40, 453-7.

(I97) Shamsi, S. A.; Danielson, N. D. Chromatographia 1995, 40, 237-46. (I98) Meynial, I.; Paquet, V.; Combes, D. Anal. Chem. 1995, 67, 1627-31. (I99) Larew, L. A.; Olsen, B. A.; Stafford, J. D.; Wilhelm, M. V. J. Chromatogr., A 1995, 692, 183-93. (I100) Thoithi, G.; Van Schepdael, A.; Herdewijn, P.; Roets, E.; Hoogmartens, J. J. Chromatogr., A 1995, 689, 247-54. (I101) Torniainen, K.; Maeki, E. J. Chromatogr., A 1995, 697, 397405. (I102) Botsoglou, N. A.; Fletouris, D. J.; Psomas, I. E.; Vassilopoulos, V. N. J. Liq. Chromatogr. 1994, 17, 4229-43. (I103) Barany, Z. B.; Lore, A.; Szasz, G.; Takacs-Novak, K.; Hermecz, I. J. Liq. Chromatogr. 1994, 17, 2031-44. (I104) Contreras-Martinez, S.; Vera-Avila, L. E. J. Chromatogr., A 1994, 667, 119-24. (I105) Giroux, L.; Barkley, D. J. Can. J. Chem. 1994, 72, 269-73. (I106) Chandler, K. J.; McCabe, J. B.; Kirkpatrick, D. L. J. Chromatogr., B: Biomed. Appl. 1994, 652, 195-202. (I107) Nesterenko, P. N.; Ivanov, A. V. J. Chromatogr., A 1994, 671, 95-9. (I108) Juskowiak, B. J. Chromatogr., A 1994, 668, 313-21. (I109) Simmons, B. R.; Stewart, J. T. J. Liq. Chromatogr. 1994, 17, 2675-90. (I110) Hu, W.; Haraguchi, H. Anal. Chim. Acta 1994, 289, 231-6. (I111) Ohtsuka, C.; Matsuzawa, K.; Wada, H.; Nakagawa, G. Anal. Chim. Acta 1994, 294, 69-74. (I112) Johnston, J. J.; Petty, E. E.; Okuno, I.; Nolte, D. L. J. Chromatogr., B: Biomed. Appl. 1995, 670, 73-9. (I113) Proksch, B.; Blanz, J.; Zeller, K. P.; Ehninger, G. J. Chromatogr., B: Biomed. Appl. 1994, 658, 349-53. (I114) Wedge, S. R.; Laohavinij, S.; Taylor, G. A.; Newell, D. R. J. Chromatogr., B: Biomed. Appl. 1995, 663, 327-35. (I115) Rivory, L. P.; Robert, J. J. Chromatogr., B: Biomed. Appl. 1994, 661, 133-41. (I116) Saini, P.; Abu-Izza, K.; Lu, D. R. J. Chromatogr., B: Biomed. Appl. 1995, 665, 155-61. (I117) Ameno, K.; Fuke, C.; Ameno, S.; Kinoshita, H.; Ijiri, I. J. Liq. Chromatogr. 1995, 18, 2115-21. (I118) Koelbl, G.; Lintschinger, J.; Kalcher, K.; Irgolic, K. J. Mikrochim. Acta 1995, 119, 113-27. (I119) Zhang, X.; Lin, C.; Liu, L.; Qiao, G. J. Chromatogr., A 1994, 684, 354-9. (I120) Hasinoff, B. B. J. Chromatogr., B: Biomed. Appl. 1994, 656, 451-5. (I121) Walsh, J. S.; Patanella, J. E.; Halm, K. A.; Facchine, K. L. Drug Metab. Dispos. 1995, 23, 869-74. (I122) Resmini, P.; Pellegrino, L.; Pagani, M. A.; De Noni, I. Ital. J. Food Sci. 1993, 5, 341-53. (I123) Abidi, S. L.; Mounts, T. L.; Rennick, K. A. J. Chromatogr. 1993, 639, 175-84. (I124) Murray, J. B.; Collier, A. K.; Arnold, J. R. P. Anal. Biochem. 1994, 218, 177-84. (I125) Misra, R. R.; Chiang, S. Y.; Swenberg, J. A. Carcinogenesis 1994, 15, 1647-52. (I126) Lazzarino, G.; Raatikainen, P.; Nuutinen, M.; Nissinen, J.; Tavazzi, B.; Di Pierro, D.; Giardina, B.; Peuhkurinen, K. Circulation 1994, 90, 291-7. (I127) Bernocchi, P.; Ceconi, C.; Cargnoni, A.; Pedersini, P.; Curello, S.; Ferrari, R. Anal. Biochem. 1994, 222, 374-9. (I128) Schobert, B. Anal. Biochem. 1995, 226, 288-92. (I129) Bedford, C. T.; Hickman, A. D.; Logan, C. J. J. Chromatogr., A 1995, 695, 123-7. (I130) Brueggemann, B.; Schlueter, H.; Verspohl, E. J.; Zidek, W. Fresenius’ J. Anal. Chem. 1994, 350, 719-21. (I131) Sypniewski, S.; Bald, E. J. Chromatogr., A 1994, 676, 321-30. (I132) Voelker, J. R.; Cobb, S. L.; Bowsher, R. R. Clin. Chem. 1994, 40(8), 1537-43. (I133) Chang, L. C.; Wang, D. P. J. Liq. Chromatogr. 1994, 17, 197180. (I134) Valladao, M.; Sandine, W. E. J. Dairy Sci. 1994, 77, 1509-14. (I135) Garcia-Sanchez, F.; Navas Diaz, A.; Garcia Pareja, A. J. Chromatogr., A 1994, 676, 347-54. (I136) Spoehrer, U.; Eyer, P. J. Chromatogr., A 1995, 693, 55-61. (I137) Ramsauer, B.; Braess, J.; Unterhalt, M.; Kaufmann, C. C.; Hiddemann, W.; Schleyer, E. J. Chromatogr., B: Biomed. Appl. 1995, 665, 183-92. (I138) Akins, D. L.; Kumar, V. T. J. Chromatogr., A 1995, 689, 26973. (I139) Oefner, P. J.; Bonn, G. K. Am. Lab. 1994, 26(9), 28C, 28D, 28F-28J. OPTICAL AND POSITIONAL ISOMERS (J1) Welch, C. J. J. Chromatogr., A 1994, 666, 3-26. (J2) Allenmark, S. G.; Andersson, S. J. Chromatogr., A 1994, 666, 167-79. (J3) Wainer, I. W. J. Chromatogr., A 1994, 666, 221-34. (J4) Okamoto, Y.; Kaida, Y. J. Chromatogr., A 1994, 666, 403-19. (J5) Davankov, V. A. J. Chromatogr., A 1994, 666, 55-76. (J6) Lipkowitz, K. B. J. Chromatogr., A 1994, 666, 493-503. (J7) Francotte, E. J. Chromatogr., A 1994, 666, 565-601. (J8) Camilleri, P.; de Biasi, V.; Hutt, A. Chem. Br. 1994, 30, 43-6. (J9) Cleveland, T. J. Liq. Chromatogr. 1995, 18, 649-71. (J10) Pirkle, W. H.; Welch, C. J. Tetrahedron: Asymmetry 1994, 5, 777-80.


563R

(J11) Isaksson, R.; Pettersson, C.; Pettersson, G.; Jonsson, S.; Stalberg, J. TrAC, Trends Anal. Chem. 1994, 13, 431-8. (J12) Oguni, K.; Oda, H.; Ichida, A. J. Chromatogr., A 1995, 694, 91-100. (J13) Maccarrone, G.; Rizzarelli, E.; Vecchio, G. NATO ASI Ser., Ser. C 1994, 448, 351-70. (J14) Issaq, H. J. Instrum. Sci. Technol. 1994, 22, 119-49. (J15) Zhou, Y.; Luan, P.; Liu, L.; Sun, Z. J. Chromatogr., B: Biomed. Appl. 1994, 659, 109-26. (J16) Gergely, A. Tech. Instrum. Anal. Chem. 1994, 14, 279-92. (J17) Lough, W. J.; Noctor, T. A. G. Prog. Pharm. Biomed. Anal. 1994, 1, 241-57. (J18) Massey, P. R.; Tandy, M. J. Chirality 1994, 6, 63-71. (J19) Tokuma, Y.; Noguchi, H. J. Chromatogr., A 1995, 694, 18193. (J20) Ruiz-Gutierrez, V.; Barron, L. J. R. J. Chromatogr., B: Biomed. Appl. 1995, 671, 133-68. (J21) Krueger, D. A. ACS Symp. Ser. 1995, No. 596, 70-8. (J22) Hyun, M. H.; Min, C. S. Chem. Lett. 1994, 1463-6. (J23) Hyun, M. H.; Jin, J. S.; Na, M. S.; Jyung, K. K. Bull. Korean Chem. Soc. 1995, 16, 344-8. (J24) Hyun, M. H.; Hwang, S.-R.; Ryoo, J.-J. Chem. Lett. 1994, 10214. (J25) Pirkle, W. H.; Liu, Y. J. Org. Chem. 1994, 59, 6911-6. (J26) Pirkle, W. H.; Terfloth, G. J. J. Chromatogr., A 1995, 704, 26977. (J27) Pirkle, W. H.; Bowen, W. E. J. High Resolut. Chromatogr. 1994, 17, 629-33. (J28) Veigl, E.; Boehs, B.; Mandl, A.; Krametter, D.; Lindner, W. J. Chromatogr., A 1995, 694, 135-50. (J29) Maher, K. M.; Taylor, D. R.; Ritchie, H. J. J. Chromatogr., A 1995, 697, 247-50. (J30) Lohmann, D.; Dappen, R. Chirality 1993, 5, 168-72. (J31) Lin, C.-E.; Lin, C.-H. J. Chromatogr., A 1994, 676, 303-9. (J32) Chankvetadze, B.; Yashima, E.; Okamoto, Y. J. Chromatogr., A 1994, 670, 39-49. (J33) Chankvetadze, B.; Yashima, E.; Okamoto, Y. J. Chromatogr., A 1995, 694, 101-9. (J34) Yashima, E.; Fukaya, H.; Okamoto, Y. J. Chromatogr., A 1994, 677, 11-9. (J35) Oliveros, L.; Lopez, P.; Minguillon, C.; Franco, P. J. Liq. Chromatogr. 1995, 18, 1521-32. (J36) Stalcup, A. M.; Williams, K. L. J. Chromatogr., A 1995, 695, 185-93. (J37) Armstrong, D. W.; Tang, Y.; Chen, S.; Zhou, Y.; Bagwill, C.; Chen, J.-R. Anal. Chem. 1994, 66, 1473-84. (J38) Hermansson, J.; Grahn, A. J. Chromatogr., A 1994, 687, 4560. (J39) Henriksson, H.; Joensson, S.; Isaksson, R.; Pettersson, G. Chirality 1995, 7, 415-24. (J40) Aubry, A.-F.; Markoglou, N.; Descorps, V.; Wainer, I. W.; Felix, G. J. Chromatogr., A 1994, 685, 1-6. (J41) Gasparrini, F.; Misiti, D.; Villani, C.; Borchardt, A.; Burger, M. T.; Still, W. C. J. Org. Chem. 1995, 60, 4314-5. (J42) Massolini, G.; De Lorenzi, E.; Ponci, M. C.; Gandini, C.; Caccialanza, G.; Monaco, H. L. J. Chromatogr., A 1995, 704, 55-65. (J43) Sinibaldi, M.; Flieger, M.; Cvak, L.; Messina, A.; Pichini, A. J. Chromatogr., A 1994, 666, 471-8. (J44) Hosoya, K.; Yoshizako, K.; Tanaka, N.; Kimata, K.; Araki, T.; Frechet, J. M. J. J. Chromatogr., A 1994, 666, 449-55. (J45) Schleimer, M.; Pirkle, W. H.; Schurig, V. J. Chromatogr., A 1994, 679, 23-34. (J46) Terfloth, G. J.; Pirkle, W. H.; Lynam, K. G.; Nicolas, E. C. J. Chromatogr., A 1995, 705, 185-94. (J47) Yashima, E.; Huang, S.; Okamoto, Y. J. Chem. Soc., Chem. Commun. 1994, 1811-2. (J48) Kobayashi, T.; Kakimoto, M.; Imai, Y. Polym. J. 1994, 26(6), 763-5. (J49) Welch, C. J. J. Chromatogr., A 1995, 689, 189-93. (J50) Ramstroem, O.; Nicholls, I. A.; Mosbach, K. Tetrahedron: Asymmetry 1994, 5, 649-56. (J51) Kempe, M.; Mosbach, K. J. Chromatogr., A 1995, 691, 31723. (J52) Kempe, M.; Mosbach, K. Tetrahedron Lett. 1995, 36, 35636. (J53) Kuester, E.; Dosenbach, C. J. High Resolut. Chromatogr. 1995, 18, 217-20. (J54) Tichy, M.; Holanova, J.; Zavada, J. J. Chromatogr., A 1994, 667, 11-7. (J55) Uray, G.; Maier, N. M.; Lindner, W. J. Chromatogr., A 1994, 666, 41-53. (J56) Knox, J. H.; Wan, Q. H. Chromatographia 1995, 40, 9-14. (J57) Pirkle, W. H.; Spence, P. L.; Lamm, B.; Welch, C. J. J. Chromatogr. 1994, 659, 69-74. (J58) Hyun, M. H.; Cho, Y. J.; Ryoo, J.-J.; Jyung, K. K.; Heo, G. S. J. Chromatogr., A 1995, 696, 173-83. (J59) Lin, J.-Y.; Yang, M.-H. J. Chromatogr., A 1994, 684, 13-21. (J60) Pirkle, W. H.; Selim, A. I. J. High Resolut. Chromatogr. 1995, 18, 353-8. (J61) Bazylak, G. J. Chromatogr., A 1994, 665, 75-86. (J62) Roussel, C.; Favrou, A. J. Chromatogr., A 1995, 704, 67-74. (J63) Josefsson, M.; Carlsson, B.; Norlander, B. J. Chromatogr., A 1994, 684, 23-7. (J64) Huynh, N.-H.; Karlsson, A.; Pettersson, C. J. Chromatogr., A 1995, 705, 275-87. 564R


(J65) Pawlowska, M.; Zukowski, J.; Armstrong, D. W. J. Chromatogr., A 1994, 666, 485-91. (J66) Iwaki, K.; Bunrin, T.; Kameda, Y.; Yamazaki, M. J. Chromatogr., A 1994, 662, 87-93. (J67) Kondo, J.; Suzuki, N.; Imaoka, T.; Kawasaki, T.; Nakanishi, A.; Kawahara, Y. Anal. Sci. 1994, 10, 17-23. (J68) Kondo, J.; Imaoka, T.; Suzuki, N.; Kawasaki, T.; Nakanishi, A.; Kawahara, Y. Anal. Sci. 1994, 10, 697-703. (J69) Nishida, Y.; Itoh, E.; Abe, M.; Ohrui, H.; Meguro, H. Anal. Sci. 1995, 11, 213-20. (J70) Toyo’oka, T.; Liu, Y.-M.; Hanioka, N.; Jinno, H.; Ando, M.; Imai, K. J. Chromatogr., A 1994, 675, 79-88. (J71) Toyo’oka, T.; Liu, Y.-M. Analyst 1995, 120(2), 385-90. (J72) Toyo’oka, T.; Liu, Y.-M. J. Chromatogr., A 1995, 689, 23-30. (J73) Penn, S. G.; Liu, G.; Bergstroem, E. T.; Goodall, D. M.; Loran, J. S. J. Chromatogr., A 1994, 680, 147-55. (J74) Stringham, R. W.; Lynam, K. G.; Grasso, C. C. Anal. Chem. 1994, 66, 1949-54. (J75) Tran, C. D.; Grishko, V. I.; Huang, G. Anal. Chem. 1994, 66, 2630-5. (J76) Haginaka, J.; Seyama, C.; Kanasugi, N. Anal. Chem. 1995, 67, 2539-47. (J77) Haginaka, J.; Kanasugi, N. J. Chromatogr., A 1995, 694, 7180. (J78) Pinkerton, T. C.; Howe, W. J.; Ulrich, E. L.; Comiskey, J. P.; Haginaka, J.; Murashima, T.; Walkenhorst, W. F.; Westler, W. M.; Markley, J. L. Anal. Chem. 1995, 67, 2354-67. (J79) Allenmark, S. Chirality 1993, 5, 295-9. (J80) Loun, B.; Hage, D. S. Anal. Chem. 1994, 66, 3814-22. (J81) Yashima, E.; Yamada, M.; Okamoto, Y. Chem. Lett. 1994, 57982. (J82) Yashima, E.; Yamada, M.; Kaida, Y.; Okamoto, Y. J. Chromatogr., A 1995, 694, 347-54. (J83) Burger, M. T.; Armstrong, A.; Guarnieri, F.; McDonald, D. Q.; Still, W. C. J. Am. Chem. Soc. 1994, 116, 3593-4. (J84) Durham, D. G.; Liang, H. Chirality 1994, 6, 240-4. (J85) Dyas, A. M.; Robinson, M. L.; Fell, A. F. J. Chromatogr. 1994, 660, 249-53. (J86) Furuta, R.; Doi, T. J. Chromatogr., A 1995, 708, 245-51. (J87) Kirkland, K. M. J. Chromatogr., A 1995, 718, 9-26. (J88) McCarthy, J. P. J. Chromatogr., A 1994, 685, 349-55. (J89) Lynam, K. G.; Nicolas, E. C. J. Pharm. Biomed. Anal. 1993, 11, 1197-206. (J90) Hermansson, J.; Hermansson, I. J. Chromatogr., A 1994, 666, 181-91. (J91) Hermansson, J.; Grahn, A. J. Chromatogr., A 1995, 694, 5769. (J92) Karlsson, A.; Pettersson, K.; Hernqvist, K. Chirality 1995, 7, 147-53. (J93) Sander, L. C.; Wise, S. A. J. Chromatogr. 1993, 656, 335-51. (J94) Dobson, G.; Christie, W. W.; Nikolova-Damyanova, B. J. Chromatogr., B: Biomed. Appl. 1995, 671, 197-222. (J95) Wyss, R. J. Chromatogr., B: Biomed. Appl. 1995, 671, 381425. (J96) Korakas, D.; Valko, K. J. Liq. Chromatogr. 1994, 17, 357184. (J97) Fukumoto, T.; Ihara, H.; Sakaki, S.; Shosenji, H.; Hirayama, C. J. Chromatogr., A 1994, 672, 237-41. (J98) Emenhiser, C.; Sander, L. C.; Schwartz, S. J. J. Chromatogr., A 1995, 707, 205-16. (J99) Nagaoka, S.; Ihara, H.; Honbo, J.; Hirayama, C.; Kurisaki, H.; Ikegami, S. Anal. Sci. 1994, 10, 543-51. (J100) Weber, T. P.; Jackson, P. T.; Carr, P. W. Anal. Chem. 1995, 67, 3042-50. (J101) Hesselink, W.; Schiffer, R. H. N. A.; Kootstra, P. R. J. Chromatogr., A 1995, 697, 165-74. (J102) Difeo, T. J.; Shuster, J. E. J. Liq. Chromatogr. 1993, 16, 390317. (J103) Ho, J. W.; Candy, L. Y. F. J. Liq. Chromatogr. 1994, 17, 41119. (J104) Abidi, S. L.; Mounts, T. L. J. Chromatogr., A 1994, 670, 6775. (J105) Abidi, S. L.; Mounts, T. L.; Rennick, K. A. J. Liq. Chromatogr. 1994, 17, 3705-25. (J106) Simms, P. J.; Hotchkiss, A. T., Jr.; Irwin, P. L.; Hicks, K. B. Carbohydr. Res. 1995, 278, 1-9. (J107) Cserhati, T.; Forgacs, E. J. Liq. Chromatogr. 1995, 18, 278399. (J108) Crini, G.; Lekchiri, Y.; Morcellet, M. Chromatographia 1995, 40, 296-302. (J109) Chen, T. M.; Chen, B. H. Chromatographia 1994, 39, 34654. (J110) Schmitz, H. H.; Emenhiser, C.; Schwartz, S. J. J. Agric. Food Chem. 1995, 43, 1212-8. (J111) Carvalho, C. R. L.; Carvalho, P. R. N.; Collins, C. H. J. Chromatogr., A 1995, 697, 289-94. (J112) Wutte, A.; Guebitz, G.; Friebe, S.; Krauss, G. J. J. Chromatogr., A 1994, 677, 186-91. (J113) Friebe, S.; Hartrodt, B.; Neubert, K.; Krauss, G. J. J. Chromatogr. 1994, 661, 7-12. (J114) Lin, J.-T.; McKeon, T. A.; Stafford, A. E. J. Chromatogr., A 1995, 699, 85-91. (J115) Brinkmann, E.; Dehne, L.; Oei, H. B.; Tiebach, R.; Baltes, W. J. Chromatogr., A 1995, 693, 271-9. (J116) Chen, S.; Pietrzyk, D. J. J. Chromatogr., A 1994, 671, 73-82.

MULTIDIMENSIONAL CHROMATOGRAPHY AND COLUMN SWITCHING (K1) Hogendoorn, E. A.; van Zoonen, P. J. Chromatogr., A 1995, 703, 149. (K2) Lough, W. J.; Noctor, T. A. G. Prog. Pharm. Biomed. Anal. 1994, 1, 241. (K3) Dawkins, J. V. Adv. Chem. Ser. 1995, 247, 197. (K4) Rippel, G.; Alattyani, E.; Szepesy, L. J. Chromatogr., A 1994, 668, 301. (K5) Rowe, K.; Bowlin, D.; Zou, M.; Davis, J. M. Anal. Chem. 1995, 67, 2994. (K6) Wheatley, J. B.; Montali, J. A.; Schmidt, D. E., Jr. J. Chromatogr., A 1994, 676, 65. (K7) Rudolphi, A.; Boos, K.-S.; Seidel, D. Chromatographia 1995, 41, 645. (K8) Kassel, D. B.; Consler, T. G.; Shalaby, M.; Sekhri, P.; Gordon, N.; Nadler, T. Tech. Protein Chem. VI, [Pap. Symp. Protein Soc.], 8th 1995, 39-46. (K9) Rule, G. S.; Mordehai, A. V.; Henion, J. Anal. Chem. 1994, 66, 230. (K10) Cai, J.; Henion, J. Anal. Chem. 1996, 68, 72. (K11) Hsu, C.-Y. L.; Walters, R. R. J. Chromatogr., B: Biomed. Appl. 1995, 667, 115. (K12) Lukulay, P. H.; McGuffin, V. L. J. Chromatogr., A 1995, 691, 171. (K13) Chiarotto, J. A.; Wainer, I. W. J. Chromatogr., B: Biomed. Appl. 1995, 665, 147. (K14) van de Merbel, N. C.; Stenberg, M.; Oeste, R.; Marko-Varga, G.; Gorton, L.; Lingeman, H.; Brinkman, U. A. Th. Chromatographia 1995, 41, 6. (K15) Arvidsson, T.; Eklund, E. J. Chromatogr., B: Biomed. Appl. 1995, 668, 91. (K16) Sancho, J. V.; Lopez, F. J.; Hernandez, F.; Hogendoorn, E. A.; van Zoonen, P. J. Chromatogr., A 1994, 678, 59. (K17) Wang, K. A.; Blain, Roger W.; Szuna, Alice J. J. Pharm. Biomed. Anal. 1994, 12, 105. (K18) Smigol, V.; Svec, F.; Frechet, J. M. J. Anal. Chem. 1994, 66, 4308. (K19) Nadler, T. K.; Paliwal, S. K.; Regnier, F. E. J. Chromatogr., A 1994, 676, 331. (K20) Rose, D. J.; Opiteck, G. J. Anal. Chem. 1994, 66, 2529. (K21) Moore, A. W., Jr.; Jorgenson, J. W. Anal. Chem. 1995, 67, 3456. (K22) Whatley, J. A. J. Chromatogr., A 1995, 697, 257. (K23) Holland, L. A.; Jorgenson, J. W. Anal. Chem. 1995, 67, 3275. (K24) Loconto, P. R.; Hussain, N. J. Chromatogr. Sci. 1995, 33, 75081. (K25) Janco, M.; Berek, D.; Prudskova, T. Polymer 1995, 36, 3295. (K26) Bandh, C.; Ishaq, R.; Broman, D.; Naef, C.; Environ. Sci. Technol. 1996, 30, 214. (K27) Kurganov, A.; Unger, K. K.; Eisenbeiss, F. Chromatographia 1994, 39, 175. (K28) Moore, A. W., Jr.; Jorgenson, J. W. Anal. Chem. 1995, 67, 3456. (K29) Fried, K. M.; Wainer, I. W. J. Chromatogr., B: Biomed. Appl. 1994, 655, 261. (K30) Herraez-Hernandez, R.; Campins-Falco, P.; Sevillano-Cabeza, A. Anal. Chem. 1996, 68, 734. (K31) Saitoh, K.; Awaka, I.; Suzuki, N. J. Chromatogr., A 1995, 693, 176. (K32) Eto, S.; Noda, H.; Noda, A. J. Chromatogr., B: Biomed. Appl. 1994, 658, 385. (K33) Nithipatikom, K.; Mizumura, T.; Gross, G. J. Anal. Biochem. 1994, 223, 280. (K34) Ohta, T.; Takamiya, I.; Takitani, S. Biomed. Chromatogr. 1994, 8, 184. (K35) Puig, D.; Barcelo, D. Chromatographia 1995, 40, 435. (K36) Pocurull, E.; Sanchez, G.; Borrull, F.; Marce, R. M. J. Chromatogr., A 1995, 696, 31. (K37) Morris, D. M.; Selinger, K. J. Pharm. Biomed. Anal. 1994, 12, 255. PREPARATIVE LC (L1) Unger, K. K., Ed. Handbook of HPLC, Part 2: Preparative Liquid Chromatography; GIT-Verlag: Darmstadt, Germany, 1994. (L2) Porsch, B. J. Chromatogr. 1994, 658, 179-94. (L3) Josic, D. BioTec (Wuerzburg, Ger.) 1992, 4(4), 41-6 (German); Chem. Abstr. 1994, 120, 72563. (L4) Mical, A. J.; Wuonola, M. A. Prog. Pharm. Biomed. Anal. 1994, 1, 261-78. (L5) Illes, J.; Aranyi, A.; Szabo, B. Magy. Kem. Lapja 1994, 49, 455-9 (Hungarian); Chem. Abstr. 1995, 122, 222973. (L6) Hicks, K. B. J. Chromatogr. Libr. 1995, 58, 361-87. (L7) Saito, H.; Mizukami, H. Kagaku Kogyo 1993, 44, 572-7 (Japanese); Chem. Abstr. 1994, 120, 220968. (L8) Golshan-Shirazi, S.; Guiochon, G. J. Chromatogr. 1994, 658, 149-71. (L9) Li, Z.; Xu, Q.; Ye, Z. Sepu 1995, 13(2), 92-5 (Chinese); Chem. Abstr. 1995, 122, 329525. (L10) Li, Z.; Ye, Z. Huagong Xuebao (Chin. Ed.) 1994, 45, 601-10 (Chinese); Chem. Abstr. 1995, 122, 34176. (L11) Tejeda-Mansir, A.; Montesinos-Cisneros, R. M.; Guzman, Z. R. Rev. Soc. Quim. Mex. 1995, 39, 166-76 (Spanish); Chem. Abstr. 1995, 123, 334020. (L12) Kaczmarski, K. Comput. Chem. Eng. 1996, 20, 49-64.

(L13) Kaczmarski, K.; Piatkowski, W. Inz. Chem. Procesowa 1993, 14, 131-44 (Polish); Chem. Abstr. 1994, 120, 63282. (L14) Cretier, G.; Rocca, J. L. J. Chromatogr. 1994, 658, 195-205. (L15) Wang, Q.; Gao, R.; Yan, B. Chin. J. Chem. 1993, 11, 71-5. (L16) Guan, H.; Guiochon, G. J. Chromatogr., A 1994, 687, 179200. (L17) Guan, H.; Guiochon, G. J. Chromatogr., A 1994, 687, 20112. (L18) Newburger, J.; DeLange, B.; Guiochon, G. J. Chromatogr., A 1994, 684, 1-11. (L19) Charton, F.; Bailly, M.; Guiochon, G. J. Chromatogr., A 1994, 687, 13-31. (L20) Dingenen, J.; Kinkel, J. N. J. Chromatogr., A 1994, 666, 62750. (L21) Mao, Q.-M; Prince, I. G.; Hearn, M. T. W. J. Chromatogr., A 1995, 691, 273-83. (L22) Luo, R. G.; Hsu, J. T. Sep. Technol. 1993, 3, 221-9. (L23) Whitley, R. D.; Zhang, X.; Wang, N.-H. L. AIChE J. 1994, 40, 1067-81. (L24) Camacho-Torralba, P. L.; Beeson, M. D.; Vigh, G.; Thompson, D. H. J. Chromatogr. 1993, 646, 259-66. (L25) Camacho-Torralba, P. L.; Beeson, M. D.; Vigh, G. J. Chromatogr., A 1995, 691, 213-6. (L26) Velayudhan, A.; Ladisch, M. R. Ind. Eng. Chem. Res. 1995, 34, 2805-10. (L27) Thompson, P. E.; Hearn, M. T. W. J. Biochem. Biophys. Methods 1995, 30, 153-61. (L28) Hodges, R. S. Canada Patent 2,059,114, Oct. 7, 1993. (L29) Wainer, I. W. J. Chromatogr., A 1994, 666, 221-34. (L30) Whatley, J. A. J. Chromatogr., A 1995, 697, 257-61. (L31) Blum, A. M.; Lynam, K. G.; Nicolas, E. C. Chirality 1994, 6, 302-13. (L32) Miller, L.; Honda, D.; Fronek, R.; Howe, K. J. Chromatogr. 1994, 658, 429-36. (L33) Wagner, J.; Hamann, H.-J.; Doepke, W.; Kunath, A.; Hoeft, E. Chirality 1995, 7, 243-7. (L34) Felix, G.; Descorps, V. Chromatographia 1995, 40, 680-3. (L35) Sun, L.; Carr, P. W. Anal. Chem. 1995, 67, 2517-23. (L36) Boschetti, E.; Guerrier, L.; Girot, P.; Horvath, J. J. Chromatogr., B: Biomed. Appl. 1995, 664, 225-31. (L37) Ando, S.; Takayanagi, H.; Fukuda, J.; Miyata, E. Res. Dev. Rev.Mitsubishi Kasei Corp. 1994, 8, 79-83 (Japanese); Chem. Abstr. 1994, 120, 227089. (L38) Hofman, Y. L.; Petrillo, K. L.; Greenblatt, H. C.; Lehrer, R.; Payne, M. S. J. Chromatogr., A 1995, 692, 233-8. (L39) Marme, S.; Unger, K. Chem.-Ing.-Tech. 1995, 67, 580-2 (German); Chem. Abstr. 1995, 123, 173778. (L40) Carta, G.; Stringfield, W. B. J. Chromatogr. 1994, 658, 40717. (L41) Gervais, D. P.; Laughinghouse, W. S.; Carta, G. J. Chromatogr., A 1995, 708, 41-53. (L42) Cooley, R. S.; Meyer, R. Isol. Purif. 1994, 2(1), 83-91. (L43) Duff, K. J.; Ludwig, R. C. Am. Lab. (Shelton, Conn.) 1994, 26(5), 32KK, 32LL, 32MM. (L44) Nicoud, R.-M.; Fuchs, G.; Adam, P.; Bailly, M.; Kuesters, E.; Antia, F. D.; Reuille, R.; Schmid, E. Chirality 1993, 5, 26771. (L45) Eleveld, J. T.; Claessens, H. A.; Germant, A. L.; Cramers, C. A. LC-GC 1994, 12, 536-40. (L46) Moriyasu, M.; Ichimaru, M.; Nishiyama, Y.; Kato, A. Bunseki Kagaku 1993, 42, 659-65 (Japanese); Chem. Abstr. 1994, 120, 27501. (L47) Fiorini, M. J. Chromatogr., A 1995, 692, 213-9. (L48) Kawai, T.; Egashira, R.; Itsuki, H.; Kawasaki, J. Kagaku Kogaku Ronbunshu 1995, 21, 158-65 (Japanese); Chem. Abstr. 1995, 122, 161092. (L49) Kodama, M.; Ishizawa, S.; Koiwa, A.; Kanaki, T.; Shibata, K.; Motomura, H. J. Chromatogr., A 1995, 707, 117-29. (L50) Firouztale’, E.; Maikner, J. J.; Deissler, K. C.; Cartier, P. G. J. Chromatogr. 1994, 658, 361-70. (L51) Miller, L.; Weyker, C. J. Chromatogr. 1993, 653, 219-28. (L52) Gildengorn, V. D.; Tyukavin, Y. A.; Volodin, V. V. Eur. J. Entomol. 1995, 92, 285. (L53) Zhang, J. Y.; Blair, I. A. J. Chromatogr., B: Biomed. Appl. 1994, 657, 23-9. (L54) Ossipov, V.; Nurmi, K.; Loponen, J.; Prokopiev, N.; Haukioja, E.; Pihlaja, K. Biochem. Syst. Ecol. 1995, 23, 213-22. (L55) Evangelisto, M. F.; Adams, R. E.; Murray, W. V.; Caldwell, G. W. J. Chromatogr., A 1995, 695, 128-31. (L56) Fetzer, J. C.; Gallegos, E. J. Polycyclic Aromat. Compd. 1992, 2, 245-51. (L57) Yao, Y.; Wang. X.; Li, Y.; Yang, D.; Zhao, L.; Zhao, L.; Zhu, Daoben Gaojishu Tongxun 1992, 2(12), 18-20 (Chinese); Chem. Abstr. 1994, 121, 98568. (L58) Guegel, A.; Muellen, K. Chromatographia 1993, 37, 387-91. (L59) Tse, D. S.; Ruoff, R. S.; Lorents, D. C.; Malhotra, R. Proc.Electrochem. Soc. 1994, 94-24 (Recent Advances in the Chemistry and Physics of Fullerenes and Related Materials), 191-9. (L60) Stevenson, S.; Dorn, H. C.; Burbank, P.; Harich, K.; Sun. Z.; Kiang, C. H.; Salem, J. R.; DeVries, M. S.; van Loosdrecht, P. H. M.; et al. Anal. Chem. 1994, 66, 2680-5. (L61) Hermann, A.; Diederich, F.; Thilgen, C.; ter Meer, H.-U.; Meuller, W. H. Helv. Chim. Acta 1994, 77, 1689-706. (L62) Gasper, M. P.; Armstrong, D. W. J. Liq. Chromatogr. 1995, 18, 1047-76.


565R

(L63) Spitsyna, N. G.; Buravov, L. I.; Lobach, A. S. J. Anal. Chem. (Transl. of Zh. Anal. Khim.) 1995, 50, 613-6. (L64) Xiao, J.; Meyerhoff, M. E. J. Chromatogr., A 1995, 715, 1929. (L65) Jinno, K.; Matsui, H.; Ohta, H.; Saito, Y.; Nakagawa, K.; Nagashima, H.; Itoh, K. Chromatographia 1995, 41, 353-60. (L66) Bergqvist, M. H. J.; Hersloef, B. G. Chromatographia 1995, 40, 129-33. (L67) Hamper, B. C.; Dukesherer, D. R.; Moedritzer, K. J. Chromatogr., A 1994, 666, 479-84. (L68) Ausserer, W. A.; Biros, M. L. BioTechniques 1995, 19 (1),136-9. (L69) Smouter, H.; Simpson, R. J. Stud. Plant Sci. 1993, 3 (Inulin and Inulin-Containing Crops), 107-13. (L70) Hicks, K. B.; Hotchkis, A. T., Jr.; Sasaki, K.; Irwin, P. L.; Doner, L. W.; Nagahashi, G.; Haines, R. M. Carbohydr. Polym. 1994, 25, 305-13. (L71) Guile, G. R.; Wong, S. Y. C.; Dwek, R. A. Anal. Biochem. 1994, 222, 231-5. (L72) Hori, H.; Ishitani, O.; Ibusuki, T.; Inoue, H. Bunseki Kagaku 1994, 43, 939-45 (Japanese); Chem. Abstr. 1995, 122, 34512. (L73) De Meulenaer, B.; Van der Meeren, P.; Vanderdeelen, J.; Baert L. J. Am. Oil Chem. Soc. 1995, 72, 1073-5. (L74) Govindachari, T. R.; Suresh, G.; Gopalakrishnan, G. J. Liq. Chromatogr. 1995, 18, 3465-71. (L75) Fronek, R.; Mardi, A.; Sheikh, J.; Howe, K.; Murphy, J.; Honda, D.; Miller, L.; Bush, H. J. Chromatogr. 1994, 658, 483-7. PRE- AND POSTCOLUMN DERIVATIZATION (M1) Krull, I. S.; Deyl, Z.; Lingeman, H. J. Chromatogr., B: Biomed. Appl. 1994, 6591(1+2), 1-17. (M2) Krull, I. S.; Szulc, M. E.; Bourque, A. J.; Zhou, F.-X.; Yu, J.; Strong, R. J. Chromatogr., B: Biomed. Appl. 1994, 659(1+2), 19-50. (M3) Barisci, J. M. Chim. Oggi. 1993, 11(10), 25-9. (M4) Ohkura, Y.; Kai, M.; Nohta, H. J. Chromatogr., B: Biomed. Appl. 1994, 659(1+2), 85-107. (M5) Hadd, A. G.; Birks, J. W. Chem. Anal. (N.Y.) 1995, 131, 20940. (M6) Riley, C. M.; Stobaugh, J. F.; Lunte, S. M. Prog. Pharm. Biomed. Anal. 1994, 1, 41-89. (M7) Toyo’oka, T. J. Chromatogr., B: Biomed. Appl. 1995, 67(1+2), 91-112. (M8) Yasaka, Y.; Tanka, M. J. Chromatogr., B: Biomed. Appl. 1994, 659(1+2), 139-55. (M9) Shimada, K.; Mitamura, K. J. Chromatogr., B: Biomed. Appl. 1994, 659(1+2), 227-41. (M10) Hase, S. J. Chromatogr. Libr. 1995, 58, 555-75. (M11) McGarvey, B. D. J. Chromatogr., B: Biomed. Appl. 1994, 659(1+2), 243-57. (M12) Kok, W. Th. J. Chromatogr., B: Biomed. Appl. 1991, 659(1+2), 127-37. (M13) Molnar-Perl, I. J. Chromatogr. 1994, 66(1-2), 43-50. (M14) Nagels, L. J.; Maes, P. C. J. Chromatogr. Libr. 1995, 58, 577606. (M15) Yu, J. H.; Li, G. D.; Krull, I. S.; Cohen, S. J. Chromatogr., B: Biomed. Appl. 1994, 658(2), 249-60. (M16) Rosenfeld, J. M.; Fang, X. J. Chromatogr., A 1995, 69(1-2), 231-7. (M17) Kou, H.-S.; Wu, H.-L.; Wang, Y.-F.; Chen, S.-H.; Wu, S.-S.; J. Chromatogr., A 1995, 710(2), 267-72. (M18) Kou, H. S.; Wu, H. L.; Chen, S. H.; Wu, S. M. J. Liq. Chromatogr. 1995, 18(12), 2323-35. (M19) Karnes, H. T.; Rahavendran, S. V.; Gui, M. Proc. SPIE-Int. Soc. Opt. Eng. 1995, 2388 (advances in Fluorescence Sensing Technology II), 21-31. (M20) Mank, A. J. G.; van der Laan, H. T. C.; Lingeman, H.; Goojer, C.; Brinkman, U. A. h.; Velthorst, N. H. Anal. Chem. 1995, 67(10), 1742-8. (M21) Vreeken, R. J.; Honing, M.; van Baar, B. L. M.; Ghijsen, R. T.; de Jong, G. J.; Brinkman, U. A. T. Biol. Mass Spectrom. 1993, 22(11), 621-32. (M22) Mamer, O. A.; Just, G.; Ji, C.-S.; Preville, P.; Watson, S.; Young, R.; Yergey, J. A. J. m. Soc. Mass Spectrom. 1994, 5(4), 2928. (M23) Lucy, C. A.; Ye, L. J. Chromatogr. 1994, 671(1-2), 121-9. (M24) Jen, J.-F.; Tsai, M.-Y. J. Chromatogr., B: Biomed. Appl. 1994, 658(1), 87-92. (M25) Ohta, T.; Takamiya, I.; Takitani, S. Biomed Chromatogr. 1994, 8(4), 184-8. (M26) Garcia-Alvarez-Coque, M. C.; Simo-Alfonso, E. F.; RamisRamos, G.; Esteve-Romero, J. S. J. Pharm. Biomed. Anal. 1995, 13(3), 237-45. (M27) Traore, F.; Prognon, P.; Mahuzier, G. Anal. Chi. Acta 1994, 294(1), 75-84. (M28) Gifford, L. A.; Owusu-Daaku, F. T. K.; Stevens, A. J. J. Chromatogr., A 1995, 715(2), 201-12. (M29) Hayashi, T.; Amino, M.; Uchida, G.; Sato, M. J. Chromatogr., B: Biomed. Appl. 1995, 665(1), 209-12. (M30) Kirschbaum, J.; Luckas, B.; Beinert, W.-D. J. Chromatogr. 1994, 661(1-2), 193-9. (M31) Bartok, T.; Szalai, G.; Lorincz, Z.; Boercsoek, G.; Sagi, F. J. Liq. Chromatogr. 1994, 17(20), 4391-403. (M32) Strydom, D. J.; Cohen, S. A. Anal. Biochem. 1994, 222(1), 19-28. 566R


(M33) Cohen, S. A.; De Antonis, K. M. J. Chromatogr. 1994, 661(12), 25-34. (M34) Cohen, S. A.; DeAntonis, K.; Michaud, D. P. Tech Protein Chem. IV. [Pap. Protein Soc. Symp.], 6th Meeting Date 1992 1993, 289-98. (M35) Idowu, O. R.; Adewuyi, G. O. J. Liq. Chromatogr. 1993, 16(17), 3773-91. (M36) Brueckner, H.; Luepke, M. J. Chromatogr., A 1995, 697(1+2), 295-307. (M37) Oravec, P.; Podhradsky, D. J. Biochem. Biophys. Methods 1995, 30(2,3), 145-52. (M38) Scaloni, A.; Simmaco, M.; Bossa, F. Amino Acids 1995, 8(3), 305-13. (M39) Saurina, J.; Hernandez-Cassou, S. J. Chromatogr., A 1994, 676(2), 311-9. (M40) Turiak, G.; Volicer, L. J. Chromatogr., A 1994, 668(2), 3239. (M41) Wintersteiger, R.; Barary, M. H.; El-Yazbi, F. A.; Sabry, S. M.; Wahbi, A.-A. M. Anal. Chim. Acta 1995, 306(2-3), 273-83. (M42) Kubo, H.; Tsujimura, A.; Kinoshita, T. Anal. Sci. 1994, 10(4), 579-82. (M43) Kubo, H. Anal. Chim. Acta 1994, 287(3), 211-4. (M44) Jackson, W. A.; Bobbitt, D. R. Anal. Chim. Acta 1994, 285(3), 309-20. (M45) Lee, W.-Y.; Nieman, T. A. J. Chromatogr. 1994, 659(1), 1118. (M46) Toyooka, T.; Chokshi, H. P.; Givens, R. S.; Carlson, R. G.; Lunte, S. M.; Kuwana, T. Biomed. Chromatogr. 1993, 7(4), 208-16. (M47) Ishida, J.; Horike, N.; Yamaguchi, M. Anal. Chim. Acta 1995, 302(1), 61-7. (M48) Ragab, G. H.; Nohta, H.; Kai, M.; Ohkura, Y.; Zaitsu, K. J. Pharm. Biomed. Anal. 1995, 13(4/5), 645-50. (M49) Ragab, G. H.; Nohta, H.; Kai, M.; Ohkura, Y. Anal. Chim. Acta 1994, 298(3), 431-8. (M50) Mukherjee, P. S.; DeSilva, K. H.; Karnes, H. T. Pharm. Res. 1995, 12(6), 930-6. (M51) Saito, M.; Ushijima, T.; Sasamoto, K.; Ohkura, Y.; Ueno, K. Anal. Sci. 1995, 11(1), 103-7. (M52) Uamaguchi, M.; Hara, S.; Obata, K. J. Liq. Chromatogr. 1995, 18(15), 2991-3006. (M53) Saito, M.; Ushijma, T.; Sasamoti, K.; Ykata, K.; Ohkura, Y.; Ueno, K. Anal. Chim. Acta 1995, 300(1-3), 243-51. (M54) Saito, M.; Chiyoda, Y.; Ushijima, T.; Sasamoto, K.; Ohkura, Y. Anal. Sci. 1994, 10(4), 679-81. (M55) Iwata, T.; Hirose, T.; Nakamura, M.; Yamaguchi, M. Analyst (Cambridge, U.K.) 1994, 119(8), 1747-51. (M56) El Mansouri, S.; Tod, M.; Leclercq, M.; Porthault, M.; Chalom, J. Anal. Chim. Acta 1994, 293(3), 245-50. (M57) Nakashima, K.; Taguchi, Y.; Kuroda, N.; Akiyama, S.; Duan, G. J. Chromatogr. Biomed. Appl. 1993, 619(1), 1-8. (M58) Slebioda, M.; Pazdro, K.; Lewandowska, J.; Kalkowski, L. Chem. Anal. (Warsaw) 1994, 39(4), 439-43. (M59) Nuijens, M. J.; Mank, A. J. G.; Gooijer, C.; Velthorst, N. H.; Hofstraat, J. W. Anal. Chim. Acta 1995, 311(1), 47-55. (M60) Nohta, H.; Sakai, F.; Kai, M.; Ohkura, Y.; Hara, S.; Yamaguchi, M. Anal. Chim. Acta 1993, 282(3), 625-31. (M61) Toyo’oka, T.; Liu, Y.-M. J. Chromatogr., A 1995, 695(1), 1118. (M62) Nakashima, K.; Hidaka, Y.; Yoshida, T.; Kuroda, N.; Akiyama, S. J. Chromatogr., B.: Biomed. Appl. 1994, 66(2), 205-10. (M63) Lores, M.; Garcia, C. M.; Cela, R. J. Chromatogr., A 1994, 683(1), 31-44. (M64) Yamaguchi, M.; Isokane, M.; Ishida, J. Anal. Sci. 1995, 11(4), 569-73. (M65) Bousquet, E.; Tirendi, S.; Prezzavento, D.; Tateo, F. F. Liq. Chromatogr. 1995, 18(10), 1933-45. (M66) Rothenberg, B. E.; Hayes, B. K.; Toomre, M.; Adriana, E.; Varki, A. Proc. Natl. Acad. Sci. U.S.A. 1993, 90(24), 1193943. (M67) Toomr, D. K.; Varki, A. Glycobiology 1994, 4(5), 653-63. (M68) Kim, Y. S.; Liu, J.; Han, X. J.; Pervin, A.; Linhardt, R. J. J. Chromatogr. Sci. 1995, 33(4), 162-7. (M69) Coquet, A.; Haerdi, W.; Degli Agosti, R.; Vuethey, J. L. Chromatographia 1991, 38(1-2), 12-16. (M70) Hong, S.-P.; Nakamura, H.; Nakajima, T. Anal. Sci. 1991, 10(4), 647-8. (M71) Thomas, J.; Mort, A. J. Anal. Biochem. 1994, 223(1), 99104. (M72) Ghosh, D.; Mathur, N. K.; Narang, C. K. Chromatographia 1993, 37(9-10), 543-5. (M73) Winters, R. A.; Zukowski, J.; Ercal, N.; Matthews, R. H.; Spitz, D. R. Anal. Biochem. 1995, 227(1), 14-21. (M74) Haj-Yehia, A. I.; Benet, L. Z. Pharm. Res. 1995, 12(1), 15560. (M75) Haj-Yehia, A. I.; Benet, L. Z. J. Chromatogr., B: Biomed. Appl. 1995, 666(1), 45-53. (M76) Di Pietra, A. M.; Gotti, R.; Bonazzi, D.; Andrisano, V.; Cavrini, V. J. Pharm. Biomed. Anal. 1994, 12(1), 91-8. (M77) Lucy, C. A.; Dinh, H. N. Anal. Chem. 1994, 66(6), 793-7. (M78) Saito, K.; Horie, M.; Nakazawa, H. Anal. Chem. 1994, 66(1), 134-8. (M79) Inoue, H.; Moritani, K.; Date, Y.; Kohashi, K.; Tsuruta, Y. Analyst (Cambridge, U.K.) 1995, 120(4), 1141-5. (M80) Zhou, Z. Y.; Dauphin, C.; Prognon, P.; Hamon, M. Chromatographia 1994, 39(3-4), 185-91.

(M81) Sonoki, S.; Sanda, A.; Hisamatsu, S. J. Liq. Chromatogr. 1994, 17(5), 1057-64. (M82) Rando, R. J.; Poovey, H. G.; Lafante, J. J.; Esmundo, F. R. J. Liq. Chromatogr. 1993, 16(18), 3977-96. (M83) Rando, R. J.; Poovey, H. G.; Gibson, R. A. J. Liq. Chromatogr. 1995, 18(14), 2743-63. (M84) Matsumoto, K.; Ichitani, Y.; Ogasawara, N.; Yuki, H.; Imai, K. J. Chromatogr., A 1994, 678(2), 241-7. (M85) Skotty, D. R.; Nieman, T. A. J. Chromatogr., B: Biomed. Appl. 1995, 665(1), 27-36. (M86) Oshima, Y. J. ADAC Int. 1995, 78(2), 528-32. (M87) Landzettel, W. J.; Hargis, K. J.; Caboot, J. B.; Adkins, K. L.; Strein, T. G.; Veening, H.; Becker, H.-D. J. Chromatogr., A 1995, 718(1), 45-51. (M88) Novak, J.; Grayeski, M. L. Microchem. J. 1994, 50(2), 15160. (M89) Demin, P.; Reynaud, D.; Pace-Asciak, C. R. Anal. Biochem. 1995, 226(2), 252-5. (M90) Andersson, A.; Ehrsson, H. J. Chromatogr., B: Biomed. Appl. 1994, 652(2), 203-10. (M91) Foley, J. P.; Dorsey, J. G. Chromatographia 1994, 18, 50311. MICROCOLUMN AND OPEN TUBULAR LC (N1) Hayakawa, M.; Sugiyama, S.; Ozawa, T. Chromatogr. Sci. Ser. 1994, 65 (Lipid Chromatographic Analysis), 273. (N2) Gohlin, K.; Buskhe, A.; Larsson, M. Chromatographia 1994, 39, 729. (N3) Steenackers, D.; Sandra, P. J. High Resolut. Chromatogr. 1994, 17, 557. (N4) Cortes, H. J.; Nicholson, L. W. J. Microcolumn Sep. 1994, 6, 257. (N5) Horka, M.; Kahle, V.; Krejci, M.; Slais, K. J. Chromatogr., A 1995, 697, 45. (N6) Horka, M.; Kahle, V.; Slais, K. J. Chromatogr., A 1994, 660, 187. (N7) Holland, L. A.; Jorgenson, J. W. Anal. Chem. 1995, 67, 3275. (N8) Kassel, D. B.; Consler, T. G.; Shalaby, M.; Sekhri, P.; Gordon, N.; Nadler, T. Tech. Protein Chem. VI, [Pap. Symp. Protein Soc.], 8th 1995, 39-46. (N9) Kasai, K.-I.; Sakurai, R.; Ishii, S.-I. Int. J. Bio-Chromatogr. 1994, 1, 83. (N10) Boughtflower, R. J.; Underwood, T.; Maddin, J. Chromatographia 1995, 41, 398. (N11) Zimina, T. M.; Smith, Roger M.; Myers, P.; King, B. W. Chromatographia 1995, 40, 662. (N12) Guo, Y.; Colon, L. A. Anal. Chem. 1995, 67, 2511. (N13) Kassel, D. B.; Shushan, B.; Sakuma, T.; Salzmann, J. P. Anal. Chem. 1994, 66, 236. (N14) Swart, R.; Kraak, J. C.; Poppe, H. Chromatographia 1995, 40, 587. (N15) Swart, R.; Kraak, J. C.; Poppe, H. J. Chromatogr., A 1994, 670, 25. (N16) Swart, R.; Kraak, J. C.; Poppe, H. J. Chromatogr., A 1995, 689, 177. (N17) Li, Y.-M.; Liao, J.-L.; Nakazato, K.; Mohammad, J.; Terenius, L.; Hjerten, S. Anal. Biochem. 1994, 223, 153. (N18) Svensson, L. A.; Karlsson, K.-E. J. Microcolumn Sep. 1995, 7, 231. (N19) Chen, J.; Steenackers, D.; Sandra, P. J. Microcolumn Sep. 1995, 7, 259. (N20) Schurig, V.; Jung, M.; Mayer, S.; Fluck, M.; Negura, S.; Jakubetz, H. J. Chromatogr., A 1995, 694, 119. (N21) Saito, Y.; Ohta, H.; Nagashima, H.; Itoh, K.; Jinno, K.; Okamoto, M.; Chen, Y.-L.; Luehr, G.; Archer, J. J. Liq. Chromatogr. 1995, 18, 1897. (N22) Saito, Y.; Ohta, H.; Terasaki, H.; Katoh, Y.; Nagashima, H.; Jinno, K. J. High Resolut. Chromatogr. 1995, 18, 569. (N23) Takeuchi, T.; Miwa, T.; Hu, R.; Chu, J. Int. Symp. Chromatogr., 35th Anniv. Res. Group Liq. Chromatogr. Jpn. 1995, 783-9. Editors: Hatano, H.; Hanai, T. Publisher: World Scientific, Singapore, Singapore. (N24) Liu, G.; Djordjevic, N.; Erni, F. Chromatographia 1994, 38, 313. (N25) Svensson, L. M.; Markides, K. E. J. Microcolumn Sep. 1994, 6, 409. (N26) Takeuchi, T.; Miwa, T. Anal. Chim. Acta 1995, 311, 231. (N27) Abbas, A. A.; Shelly, D. C. J. Chromatogr., A 1995, 691, 37. (N28) Howard, A. L.; Thomas, C. L. B.; Taylor, L. T. Anal. Chem. 1994, 66, 1432. (N29) Saz, J. M.; Diez-Masa, J. C. J. Liq. Chromatogr. 1994, 17, 499. (N30) Siddiqui, A.; Shelly, D. C. J. Chromatogr., A 1995, 691, 55. (N31) LaCourse, W. R.; Owens, G. S. Anal. Chim. Acta 1995, 307, 301. (N32) Bohs, C. E.; Linhares, M. C.; Kissinger, P. T. Curr. Sep. 1994, 12, 181. (N33) Ocvirk, G.; Verpoorte, E.; Manz, A.; Grasserbauer, M.; Widmer, H. M. Anal. Methods Instrum. 1995, 2, 74. (N34) Berloni, A.; Cappiello, A.; Famiglini, G.; Palma, P. Chromatographia 1994, 39, 279. (N35) Tong, D.; Bartle, K. D.; Clifford, A. A.; Robinson, R. E. Analyst (Cambridge, U.K.) 1995, 120, 2461.

TRACE ANALYSIS (O1) Slobodnik, J.; van Baar, B. L. M.; Brinkman, U. A. Th. J. Chromatogr., A 1995, 703, 81. (O2) Linscheid, M.; Westmoreland, D. G. Pure Appl. Chem. 1994, 66, 1913. (O3) Molina, C.; Durand, G.; Barcelo, D. J. Chromatogr., A 1995, 712, 113. (O4) Chiron, S.; Papilloud, S.; Haerdi, W.; Barcelo, D. Anal. Chem. 1995, 67, 1637. (O5) Crescenzi, C.; Di Corcia, A.; Marchese, S.; Samperi, R. Anal. Chem. 1995, 67, 1968. (O6) Volmer, D.; Levsen, K.; Engewald, W. Vom Wasser 1994, 82, 335. (O7) Bonchin-Cleland, S. L.; Ding, H.; Caruso, J. A. Am. Lab. 1995, 27, 34N. (O8) Byrdy, F. A.; Caruso, J. A. Environ. Health Perspect. Suppl. 1995, 103(Suppl. 1), 21. (O9) Heumann, K. G.; Rottmann, L.; Vogl, J. J. Anal. At. Spectrom. 1994, 9, 1351. (O10) Byrdy, F. A.; Olson, L. K.; Vela, N. P.; Caruso, J. A. J. Chromatogr., A 1995, 712, 311. (O11) Seubert, A.; Wilhartitz, P. Krismer, R.; Krabichler, H. Mikrochim. Acta 1995, 117, 245. (O12) Fu, C.-G.; Xu, H.-D. Analyst (Cambridge, U.K.) 1995, 120, 1147. (O13) Murata, H.; Shoji, H.; Oshikata, M.; Harada, K.-I.; Suzuki, M.; Kondo, F.; Goto, H. J. Chromatogr., A 1995, 693, 263. (O14) Lu, G.; Jun, H. W. J. Liq. Chromatogr. 1995, 18, 155. PHYSIOCHEMICAL MEASUREMENTS (P1) Dorsey, J. G.; Khaledi, M. G. J. Chromatogr. 1993, 656, 48599. (P2) Hsieh, M.-M.; Dorsey, J. G. Anal. Chem. 1995, 67, 48-57. (P3) Valko, K.; Snyder, L. R.; Glajch, J. L. J. Chromatogr. 1993, 656, 501-19. (P4) Kaliszan, R. Mater. Eng. (N.Y.) 1995, 9, 87-103. (P5) Cichna, M.; Markl, P.; Huber, J. F. K. J. Pharm. Biomed. Anal. 1995, 13, 339-51. (P6) Nasal, A.; Sznitowska, M.; Bucinski, A.; Kaliszan, R. J. Chromatogr., A 1995, 692, 83-9. (P7) Kaliszan, R.; Nasal, A.; Bucinski, A. Eur. J. Med. Chem. 1994, 29, 163-70. (P8) Pagliara, A.; Khamis, E.; Trinh, A.; Carrupt, P.-A.; Tsai, R.-S.; Testa, B. J. Liq. Chromatogr. 1995, 18, 1721-45. (P9) Henczi, M.; Nagy, J.; Weaver, D. F. J. Liq. Chromatogr. 1994, 17, 2605-13. (P10) Kaune, A.; Knorrenschild, M.; Kettrup. A. Fresenius’ J. Anal. Chem. 1995, 352, 303-12. (P11) Fekete, J.; Morovjan, G.; Csizmadia, F.; Darvas, F. J. Chromatogr., A 1994, 660, 33-46. (P12) Makovskaya, V.; Dean, J. R.; Tomliinson, W. R.; Hitchen, S. M.; Comber, M. Anal. Chim. Acta 1995, 315, 183-92. (P13) Kim, K. H. J. Comput-Aided Mol. Des. 1995, 9, 308-18. (P14) Kim, K. H. Quant. Struct.-Act. Relat. 1995, 14, 8-18. (P15) Luco, J. M.; Yamin, L. J.; Ferretti, H. F. J. Pharm. Sci. 1995, 84, 903-8. (P16) Abraham, M. H.; Chadha, H. S.; Leo. A. J. J. Chromatogr., A 1994, 685, 203-11. (P17) Yamagami, C.; Takao, N. Chem. Pharm. Bull. 1993, 41, 6948. (P18) Yamagami, C.; Yokota, M.; Takao, N. J. Chromatogr., A 1994, 662, 49-60. (P19) Yamagami, C.; Yokota, M.; Takao, N. Chem. Pharm. Bull. 1994, 42, 907-12. (P20) Yamagami, C.; Takao, N. Chem. Pharm. Bull. 1991, 39, 121721. (P21) Wilce, M. C. J.; Aguilar, M.-I.; Hearn, M. T. W. Anal. Chem. 1995, 67, 1210-9. (P22) Yamaki, S.; Okuyama, T.; Shinoda, T. Kuromatogurafi 1994, 15, 280-1 (Japanese); Chem. Abstr. 1995, 122, 229717. (P23) Rothemund, S.; Krause, E.; Ehrlich, A.; Bienert, M.; Glusa, E.; Verhallen, P. J. Chromatogr., A 1994, 661, 77-82. (P24) Zou, H.; Zhang, Y.; Hong, M.; Lu, P. Prog. Nat. Sci. 1995, 5, 106-12. (P25) Baj, S.; Dawid, M. J. Liq. Chromatogr. 1994, 17, 3933-49. (P26) Forgacs, E.; Cserhati, T. J. Chromatogr., B: Biomed. Appl. 1995, 664, 277-85. (P27) Forgacs, E. J. Liq. Chromatogr. 1993, 16, 3757-72. (P28) Hamoir, T.; Massart, D. L. J. Chromatogr., A 1994, 673, 1-10. (P29) Woolston, C. R. J.; Lee, J. B.; Swinbourne, F. J. Indian J. Chem., Sect. B: Org. Chem. Incl. Med. Chem. 1994, 33B, 590-2. (P30) Masumoto, K.; Takeyasu, A.; Oizumi, K.; Kobayashi, T. Yakugaku Zasshi 1995, 115, 213-20 (Japanese); Chem. Abstr. 1995, 123, 101979. (P31) Ritter, S.; Hauthal, W. H.; Maurer, G. J. Chem. Eng. Data 1994, 39, 414-7. (P32) Jiang, X.; Zhu, Z.; Hua, X.; Daogi, C. Nongyao Kexue Yu Guanli 1993, (1), 33-6 (Chinese); Chem. Abstr. 1994, 120, 71389. (P33) Jiang, X.; Zhu, Z.; Hua, X.; Cai, D. Nongyao Kexue Yu Guanli 1993, (2), 29-34 (Chinese); Chem. Abstr. 1994, 120, 71390. (P34) Reichelova, V.; Albertioni, F.; Liliemark, J. J. Chromatogr., A 1994, 667, 37-45. (P35) Slater, B.; McCormack, A.; Avdeef, A.; Comer, J. E. A. J. Pharm. Sci. 1994, 83, 1280-3.


567R

(P36) Hardcastle, J. E.; He, M.; Begum, B.; Vermillion-Salsbury, R. J. Chromatogr., A 1995, 691, 225-9. (P37) Sereda, T. J.; Mant, C. T.; Quinn, A. M.; Hodges, R. S. J. Chromatogr. 1993, 646, 17-30. (P38) Hendriks, M. M. W. B.; Coenegracht, P. M. J.; Doornbos, D. A. Chemom. Intell. Lab. Syst. 1994, 25, 227-39. (P39) Ashton, D. S.; Beddell, C.; Ray, A. D.; Valko, K. J. Chromatogr., A 1995, 707, 367-72. (P40) Mikhalkin, A. P.; Vlasov, V. N. Kolloidn. Zh. 1993, 55, 10010 (Russian); Chem. Abstr. 1994, 120, 107647. (P41) Gonzalez, A. G.; Herrador, M. A.; Asuero, A. G. Int. J. Pharm. 1995, 120, 215-20. (P42) Henczi, M.; Nagy, J.; Weaver, D. F. J. Pharm. Pharmacol. 1995, 47, 345-7. (P43) Semenova, O. P.; Timerbaev, A. R.; Bonn, G. K. J. Chromatogr., A 1994, 667, 327-33. (P44) Osmialowski, K.; Cisowski, W.; Dzikowska, J. Acta Chromatogr. 1993, 2, 65-71. (P45) Jingde, H.; Ying, Z. Fenxi Huaxue 1994, 22, 805-7 (Chinese); Chem. Abstr. 1994, 121, 248591. (P46) Sun, X.; Xin, M.; Zhao, J. J. Liq. Chromatogr. 1994, 17, 118394. (P47) Kumar, K.; Sukumaran, K.; Taylor, S.; Chang, C. A.; Nunn, A. D.; Tweedle, M. F. J. Liq. Chromatogr. 1994, 17, 3735-46. (P48) Altomare, C.; Carotti, A.; Cellamare, S..; Carrieri, A.; Ciabatti, R.; Malabarba, A. J. Pharm. Pharmacol. 1994, 46, 994-9. (P49) Tsantili-Kakoulidou, A.; Filippatos, E.; Todoulou, O.; PapadakiValiraki, A. J. Chromatogr. 1993, 654, 43-52. (P50) Sadlej-Sosnowska, N. J. Pharm. Biomed. Anal. 1995, 13, 7014. (P51) Loukas, Y. L.; Antoniadou-Vyza, E.; Papadaki-Valiraki, A.; Machera, K. G. J. Agric. Food Chem. 1994, 42, 944-8. (P52) Sutheimer, S. H.; Cabaniss, S. E. Anal. Chem. 1995, 67, 23429. (P53) Chellquist, E. M.; Searle, R. J. Pharm. Biomed. Anal. 1993, 11, 985-92. (P54) Bian, H. J.; Hou, J. G.; Gao, J. Z.; Kang, J. W.; Xin, W. L. Chin. Chem. Lett. 1994, 5, 389-92. (P55) Zou, H.; Zhang, Y.; Lu, P. Anal. Chim. Acta 1995, 310, 46171. (P56) Rodriguez, M. A.; Sanchez, M. J.; Gonzalez, V.; Montelongo, G. Chromatographia 1994, 38, 342-8. (P57) Honda, S. J. Chromatogr. Libr. 1995, 58, 211-31. (P58) Kaliszan, R.; Nasal, A.; Turowski, M. Biomed. Chromatogr. 1995, 9, 211-5. (P59) Hage, D. S.; Noctor, T. A. G.; Wainer, I. W. J. Chromatogr., A 1995, 693, 23-32. (P60) Loun, B.; Hage, D. S. Anal. Chem. 1994, 66, 3814-22. (P61) Loun, B.; Hage, D. S. J. Chromatogr., B: Biomed. Appl. 1995, 665, 303-14. (P62) Tiller, P. R.; Mutton, I. M.; Lane, S. J.; Bevan, C. D. Rapid Commun. Mass Spectrom. 1995, 9, 261-3. (P63) Ibrahim, H.; Aubry, A.-F. Anal. Biochem. 1995, 229, 272-7. (P64) Blondelle, S. E.; Perez-Paya, E.; Allicotti, G.; Forood, B.; Houghten, R. A. Biophys. J. 1995, 69, 604-11. (P65) Bellot, J. C.; Condoret, J. S. Process Biochem. (Barking, UK) 1993, 28, 365-76. (P66) Miyabe, K. Adsorpt. News 1994, 8(1), 16-20 (Japanese); Chem. Abstr. 1995, 122, 143205. (P67) Eltekova, N. A.; Eltekov, Y. A. Carbon 1993, 31, 957-61. (P68) Rodrigues, A. E.; Lu, Z. P.; Loureiro, J. M.; Pais, L. S. J. Chromatogr., A 1995, 702, 223-31. (P69) Martinez, M.; Carrancio, A.; Casillas, J. L.; Aracil, J. Ind. Eng. Chem. Res. 1995, 34, 4486-93. (P70) Renard, J.; Vidal-Madjar, C.; Lapresle, C. J. Colloid Interface Sci. 1995, 174, 61-7. (P71) Kazakevich, Y. V.; McNair, H. M. J. Chromatogr. Sci. 1993, 31, 317-22. (P72) Moeckel, H. J. J. Chromatogr., A 1994, 675, 13-28. (P73) Guillaume, Y.; Guinchard, C. J. Liq. Chromatogr. 1994, 17, 2809-20. (P74) Guillaume, Y.; Guinchard, C. Chromatographia 1995, 41, 847. (P75) Hou, J.; Xu, X. Fenxi Huaxue 1995, 23, 497-501 (Chinese); Chem. Abstr. 1995, 123, 47397. (P76) Roush, D. J.; Gill, D. S.; Willson, R. C. J. Chromatogr. 1993, 653, 207-18. (P77) Zimmerman, S. C.; Saionz, K. W. J. Am. Chem. Soc. 1995, 117, 1175-6. (P78) Yang, S. K.; Lu, X. L. J. Pharm. Biomed. Anal. 1993, 11, 11818. (P79) Kita, H.; Kaneko, Y. Nippon Shashin Gakkaishi 1994, 57, 344-8 (Japanese); Chem. Abstr. 1995, 123, 97643. (P80) Kang, C. H. Nonmunjip-Cheju Taehakkyo, Chayon Kwahakpyon 1992, 35, 119-29 (Korean); Chem. Abstr. 1994, 120, 22783. (P81) Silveston, R.; Kronberg, B. J. Chromatogr. 1994, 659, 43-56. (P82) Park, J. H.; Jang, M. D.; Chae, J. J.; Kim, H. C.; Suh, J. K. J. Chromatogr. 1993, 656, 69-79. (P83) Hou, J.; Lu, W. Huaxue Xuebao 1994, 52, 500-5 (Chinese); Chem. Abstr. 1994, 121, 49408. (P84) Su, W.; Gregory, R. B.; Gilpin, R. K. J. Chromatogr. Sci. 1994, 32, 279-81. (P85) Egekeze, J. O.; Danielski, M. C.; Grinberg, N.; Smith, G. B.; Sidler, D. R.; Perpall, H. J.; Bicker, G. R.; Tway, P. C. Anal. Chem. 1995, 67, 2292-5. 568R


(P86) Nishikawa, T.; Hasumi, H.; Suzuki, S.; Kubo, H.; Ohtani, H. Pharm. Res. 1993, 10, 1785-9. (P87) Soentjens-Werts, V.; Dubois, J. G.; Atassi, G.; Hanocq, M. Talanta 1995, 42, 581-9. (P88) Buist, G. J.; Barton, J. M.; Howlin, B. J.; Jones, J. R.; Parker, M. J. J. Mater. Chem. 1995, 5, 213-7. (P89) Baj, S.; Dawid, M. Chem. Anal. (Warsaw) 1994, 39, 33-7. (P90) Guan, Y.; Luo, L.; Du, H.; Tang, W. Wuji Huaxue Xuebao 1992, 8, 464-6 (Chinese); Chem. Abstract 1994, 120, 87754. (P91) Berger, G.; Girault, G.; Galmiche, J.-M.; Pezennec, S. J. Bioenerg. Biomembr. 1994, 26, 335-46. (P92) Hsieh, F. Y. L.; Tong. X.; Wachs, T.; Ganem, B.; Henion, J. Anal. Biochem. 1995, 229, 20-5. (P93) Lowther, W. T.; Dunn, B. M. Lett. Pept. Sci. 1994, 1, 89-94. (P94) Nunez, A.; Piazza, G. J. Lipids 1995, 30, 129-33. (P95) Alebic-Kolbah, T.; Wainer, I. W. J. Chromatogr. 1993, 653, 122-9. (P96) Renard, J.; Vidal-Madjar, C.; Sebille, B.; Lapresle, C. J. Mol. Recognit. 1995, 8, 85-9. (P97) Villarejo, A. D.; Solelo, J. B.; Doadrio, J. C.; Orenga, R.; Mayorga, A. Ecletica Quim. 1994, 19, 33-47. (P98) Lee, H.; Jang, W. C.; Lee, H. S. Arch. Pharmacal Res. 1994, 17, 378-80. (P99) Vilanova, B.; Munoz, F.; Donoso, J.; Frau, J.; Garcia Blanco, F. J. Pharm. Sci. 1994, 83, 322-7. (P100) Zajac, M.; Stanisz, B. Acta Pol. Pharm. 1994, 51, 127-32. (P101) Oh, I. J.; Lee, J. M.; Lee, Y. B.; Shin, S. C.; Choi, B. G. Arch. Pharmacal Res. 1995, 18, 75-8. (P102) Wahbi, A.-A. M.; El-Walily, A.-F. M.; Hassan, E. M.; Saliman, F. G.; El-Gendi, A. J. Pharm. Biomed. Anal. 1995, 13, 77784. (P103) Taylor, R. B.; Richards, R. M. E.; Low, A. S.; Hardie, L. Int. J. Pharm. 1994, 102, 201-6. (P104) Hsu, H.-C.; Wang, C.-F.; Lo, C.-S. Chin. Pharm. J. (Tappei) 1994, 46, 33-44. (P105) Mathew, M.; Das Gupta, V. Drug Dev. Ind. Pharm. 1995, 21, 257-64. (P106) El-Yazigi, A.; Wahab, F. A.; Afrane, B. J. Chromatogr., A 1995, 690, 71-6. (P107) Han, J.; Wang, L.; Su, D. Shenyang Yaoxueyuan Xuebao 1993, 10, 171-5 (Chinese); Chem. Abstr. 1994, 120, 307259. (P108) Moreau, J. L.; Azza, S.; Bigey, F.; Arnaud, A.; Galzy, P. J. Chromatogr., B: Biomed. Appl. 1994, 656, 197-202. (P109) Bednarski, P. J.; Truembach, B. Transition Met. Chem. (London) 1994, 19, 513-7. (P110) Loukas, Y. L.; Antoniadou-Vyza, E.; Papadaki-Valiraki, A. J. Chromatogr., A 1994, 677, 53-61. (P111) Van Schepdael, A.; Macken, E.; Busson, R.; Janssen, G.; Herdewijn, P.; Roets, E.; Hoogmartens, J. J. Chromatogr. 1993, 657, 208-12. (P112) Lai, E. P. C.; Vucic, R. S. Fresenius’ J. Anal. Chem. 1993, 347, 427-22. (P113) Purcell, A. W.; Aguilar, M. I.; Hearn, M. T. W. J. Chromatogr., A 1995, 711, 61-70. (P114) Purcell, A. W.; Aguilar, M. I.; Hearn, M. T. W. J. Chromatogr., A 1995, 711, 71-9. (P115) Purcell, A. W.; Aguilar, M-I; Wettenhall, R. E. H.; Hearn, M. T. W. Pept. Res. 1995, 8, 160-70. (P116) Richards, K. L.; Aguilar, M. I.; Hearn, M. T. W. J. Chromatogr., A 1994, 676, 33-41. (P117) Hodges, R. S.; Zhu, B-Y; Zhou, N. E.; Mant, C. T. J. Chromatogr., A 1994, 676, 3-15. (P118) Sereda, T. J.; Mant, C. T.; Hodges, R. S. J. Chromatogr., A 1995, 695, 205-21. (P119) Krause, E.; Beyermann, M.; Dathe, M.; Rothemund, S.; Bienert, M. Anal. Chem. 1995, 67, 252-8. (P120) Rothemund, S.; Krause, E.; Beyermann, M.; Dathe, M.; Engelhardt, H.; Bienert, M. J. Chromatogr., A 1995, 689, 21926. (P121) Shi, Y.; Ma, F.; Geng, X Fenxi Huaxue 1994, 22, 453-6 (Chinese); Chem. Abstr. 1994, 121, 199920. (P122) Yali, S.; Ma, F.; Xindu, G. Fenxi Huaxue 1994, 22, 712-5. (P123) Shi, Y.-L.; Ma, F.; Geng, X.-D. Gaodeng Xuexiao Huaxue Xuebao 1994, 15, 1288-91 (Chinese); Chem. Abstr. 1995, 122, 75710. (P124) Wicar, S.; Mulkerrin, M. G.; Bathory, G.; Khundkar, L. H.; Karger, B. L. Anal. Chem. 1994, 66, 3908-15. (P125) Salom, D.; Bano, M. C.; Braco, L.; Abad, C. Biochem. Biophys. Res. Commun. 1995, 209, 466-73. (P126) Alfredson, T. V.; Bruins, P. W.; Maki, A. H.; Excoffier, J. L. J. Chromatogr. Sci. 1994, 32, 132-8. (P127) Potaman, V. N.; Chernov, I. P.; Demidov, V. V. J. Chromatogr. 1993, 648, 151-6. (P128) Astafieva, I.; Eberlein, G.; Nilsson, L.; Shortt, D. W.; Wyatt, P. J. Am. Biotechnol. Lab. 1995, 13(4), 30. (P129) Casarini, D.; Lunazzi, L.; Alcaro, S.; Gasparrini, F.; Villani, C. J. Org. Chem. 1995, 60, 5515-9. (P130) Vilani, C.; Pirkle, W. H. Tetrahedron: Asymmetry 1995, 6, 2730. (P131) Schure, M. R. Spec. Publ.-R. Soc. Chem. 1994, 139 (Chemically Modified Surfaces), 181-9. (P132) Schunk, T. C.; Burke, M. F. J. Chromatogr. 1993, 656, 289316. (P133) Yarovsky, I.; Aguilar, M.-I.; Hearn, M. T. W. J. Chromatogr., A 1994, 660, 75-84.

A19600202

Liquid Chromatography: Theory and Methodology - ACS Publications

Recommend Documents