Optimization Of Chromatographic Selectivity

This is the first detailed description of method development in chromatography - the overall process of which may be summarized as: method selection, phase selection, selectivity optimization, and system optimization. All four aspects receive attention in this book. Chapter 1 gives a short introduction, describes chromatographic theory and nomenclature, and outlines the method development process. Chapter 2 describes guidelines for method selection, and quantitative concepts for characterizing and classifying chromatographic phases. Selective separation methods, from both gas and liquid chromatography are given in Chapter 3; the main parameters of each method are identified and simple, quantitative relations are sought to describe their effects. Criteria by which to judge the quality of separation are discussed in Chapter 4 with clear recommendations for different situations. The specific problems involved in the optimization of chromatographic selectivity are explained in Chapter 5. Optimization procedures, illustrated by examples, are extensively described and compared on the basis of a number of criteria. Suggestions are made both for the application of different procedures and for further research. The optimization of programmed analysis receives special attention in Chapter 6, and the last chapter summarizes the optimization of the chromatographic system, including the optimization of the efficiency, sensitivity and instrumentation. Those involved in developing chromatographic methods or wishing to improve existing methods will value the detailed, structured way in which the subject is presented. Because optimization procedures and criteria are described as elements of a complete optimization package, the book will help the reader to understand, evaluate and select current and future commercial systems.

High Performance Liquid Chromatography Edited by Phyllis Brown and Richard Hartwick This contributed volume is designed to consolidate the basic theories of chromatography along with the more exciting developments in the field. This monograph addresses some questions that concern researchers in separation science, including: what is the current state of the art in liquid chromatography; has the development of liquid chromatography plateaued; if so, what new methods will take its place or complement it; and if not, where will the new frontiers be and what direction will liquid chromatography take? 1989 (0 471-84506-X) 688 pp. Quantitative Structure-Chromatographic Retention Relationships R. Kaliszan Written by a pioneer in the field, this book extends and updates research on quantitative structure retention relationships by consolidating and critically reviewing the extensive literature on the subject, while also providing the basic theoretical and practical information required in all investigations involving chromatography, analytical chemistry, biochemistry, and pharmaceutical research. Among the topics covered are the nature of chromatographic interactions, molecular interpretation of distribution processes in chromatography, topological indices as retention descriptors, and multiparameter structure-chromatographic retention relationships. 1987 (0 471-85983-4) 303 pp. Detectors for Liquid Chromatography Edited by Edward S. Yeung With its singular coverage of this fast-growing field, Detectors for Liquid Chromatography presents the state of the art in this subject area. It offers a comprehensive examination of the basic principles behind the detector response, instrumentation, and selected applications for comparison and evaluation of potential. Specifically, topics given in-depth coverage include polarimetric, indirect absorbance, refractive index detectors, absorption detectors for HPLC, FTIR and fluorometric detection, detection based on electrical and electromechanical measurements, and mass spectroscopy as an on-line detector for HPLC. 1986 (0 471-82169-1) 366 pp.

The only topical HPLC book to focus on optimization, this volume addresses the needs of HPLC users who wish to constantly improve their methods, in particular in terms of throughput, accuracy and cost-effectiveness. This handbook features contributions from such bestselling authors as John W. Dolan, Michael McBrien, Veronika R. Meyer, Uwe D. Neue, Lloyd R. Snyder, and Klaus K. Unger, as well as from scientists working for major companies, including Agilent, AstraZeneca, Merck, Schering, Tosoh Biosep, VWR, and Waters. It covers essential aspects of optimization in general, optimization in different LC-modi, hyphenated techniques and computer-aided optimization. The whole is rounded off with a section of user reports.

As in all chemical separation methods, selectivity is an important parameter for achieving separation. Also important is the optimization of the separation conditions to achieve high plate counts, speed and resolution. Obviously, in any given separation process, no separation can take place in the absence of selectivity even if millions of theoretical plates are easily attained.This thematic issue of Journal of Chromatography A recognizes the importance of selectivity and optimization in maximizing separation in capillary electrophoresis by providing the reader with several review and research articles from experts in the field. The thematic issue is organized into six major parts, and in each part pertinent review articles are collected first followed by a number of original contributions.This special volume has treated many of the selectivity and optimization issues that address the needs of those who use capillary electrophoresis. This will facilitate the widespread use of capillary electrophoresis as an important analytical separation tool for solving separation problems of practical importance in the life and other sciences.

This book brings together a number of studies which examine the ways in which the retention and selectivity of separations in high-performance liquid chromatography are dependent on the chemical structure of the analytes and the properties of the stationary and mobile phases. Although previous authors have described the optimisation of separations by alteration of the mobile phase, little emphasis has previously been reported of the influence of the structure and properties of the analyte. The initial chapters describe methods based on retention index group increments and log P increments for the prediction of the retention of analytes and the ways in which these factors are influenced by mobile phases and intramolecular interactions. The values of a wide range of group increments in different eluents are tabulated. Different scales of retention indices in liquid chromatography are described for the comparison of separations, the identification of analytes and the comparison of stationary phases. Applications of these methods in the pharmaceutical, toxicology, forensic, metabolism, environmental, food and other fields are reviewed. The effects of different mobile phases on the selectivity of the retention indices are reported. A compilation of sources of reported retention index values are given. Methods for the comparison of stationary phases based on the interactions of different analytes are covered, including lipophilic and polar indices, shape selectivity comparisons, their application to novel stationary phases, and chemometric methods for column comparisons.

Chromatography Today provides a comprehensive coverage of various separation methods: gas, liquid, thin-layer, and supercritical fluid-chromatography, and capillary electrophoresis. Particular attention is paid to the optimization of these techniques in terms of kinetic parameters and retention mechanisms. When these facts are understood, method selection and optimization becomes a more logical process. Sample preparation methods are treated fully as they frequently represent an integral part of the total analytical method. Also described are preparative-scale separations used for isolating significant amounts of product which are generally achieved under conditions that are not identical to those used for analytical separations. The most common hyphenated methods used for sample identification are discussed from the perspective of the information they yield and the requirements of common interfaces. The scope and level of discussion are designed to be appropriate for various user groups. This book should be suitable for use as a graduate-level student textbook in separation science, a text for professional institutes offering short courses in chromatography, and as a self-study guide for chromatographers to refresh their knowledge of the latest developments in the field. The book is extensively illustrated with over 200 figures, 110 tables and 3,300 references, largely to the contemporary literature.

Delineating its usage in separation, purification and detection processes across a variety of disciplines, from industry to applied research, this work discusses the principles, techniques and instrumentation involving HPLC within a detailed framework. Over 100 tables present previously scattered experimental data.