Instrumental Liquid Chromatography

Instrumental Liquid Chromatography

Publisher Description

Details the principles and mechanisms of, and the equipment and optimal working conditions for, the liquid-chromatographic separation of well-defined oligomeric species and fraction with narrow molecular weight distribution. The work provides a complete description of the applications and possible performance of liquid chromatography in the field of oligomer separation.

Instrumentation for High Performance Liquid Chromatography

Instrumental techniques of analysis have now moved from the confines of the chemistry laboratory to form an indispensable part of the analytical armoury of many workers involved in the biological sciences. It is now quite out of the question to considcr a laboratory dealing with the analysis of biological materials that is not equipped with an extensive range of instrumentation. Recent years have also seen a dramatic improvement in the ease with which such instruments can be used, and the quality and quantity of the analytical data that they can produce. This is due in no sm all part to the ubiquitous use of microprocessors and computers for instrumental control. However, under these circumstances there is areal danger of the analyst adopting a 'black box' mentality and not treating the analytical data produced in accordance with the limitations that may be inherent in the method used. Such a problem can only be overcome if the operator is fully aware of both the theoretical and instrumental constraints relevant to the technique in question. As the complexity and sheer volume of material in undergraduate courses increases, there is a tendency to reduce the amount of fundamental material that is taught prior to embarking on the more applied aspects. This is nowhere more apparent than in the teaching of instrumental techniques of analysis.

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.

The rapid development of new packings for aqueous size-exclusion chromatography has revolutionized this field. High resolution non-adsorptive columns now make possible the efficient separation of proteins and the rapid and precise determination of the molecular weight distribution of synthetic polymers. This technology is also being applied to the separation of small ions, the characterization of associating systems, and the measurement of branching. At the same time, fundamental studies are elucidating the mechanisms of the various chromatographicprocesses.These developments in principles and applications are assembled for the first time in this book. Fundamental issues are dealt with: the roles of pore structure and macromolecular dimensions, hydrophobic and electrostatic effects, and the determination and control of column efficiency. High-performance packings based on derivatized silica are reviewed in detail. Special techniques are thoroughly described, including SEC/LALLS, inverse exclusion chromatography, and frontal zone chromatography. Attention is focussed on special applications of size-exclusion methods, such as the characterization of micelles, separations of inorganic ions, and Hummel-Dreyer and related methods for equilibrium systems. Protein chromatography is dealt with in both dedicated sections and throughout the book as a whole.This is a particularly comprehensive and authoritative work - all the contributions review broad topics of general significance and the authors are of high repute. The material will be of special value for the characterization of synthetic water-soluble polymers, especially polyelectrolytes. Biochemists will find fundamental and practical guidance on protein separations. Researchers confronted with solutes that exhibit complex chromatographic behavior, such as humic acids, aggregating proteins, and micelles should find the contents of this volume illuminating.

The primary aim of this volume is to make the chemist familiar with the numerous stationary phases and column types, with their advantages and disadvantages, to help in the selection of the most suitable phase for the type of analytes under study. The book also provides detailed information on the chemical structure, physico-chemical behaviour, experimental applicability, physical data of liquid and solid stationary phases and solid supports. Such data were previously scattered throughout the literature. To understand the processes occurring in the separation column and to offer a manual both to the beginner and to the experienced chromatographer, one chapter is devoted to the basic theoretical aspects. Further, as the effectiveness of the stationary phase can only be considered in relation to the column type, a chapter on different column types and the arrangement of the stationary phase within the column is included.The secondary aim of this book is to stimulate the development of new and improved standardized stationary phases and columns, in order to improve the reproducibility of separations, as well as the range of applications.

This is the first book to focus on the latest developments in hyphenated techniques using supercritical fluids. The advantages of SFC in hyphenation with various detection modes, such as FTIR, MS, MPD and ICP and others are clearly featured throughout the book. Special attention is paid to coupling of SFE with GC or SFC.In this edited volume, chapters are written by leading experts in the field. The book will be of interest to professionals in academia, as well as to those researchers working in an industrial environment, such as analytical instrumentation, pharmaceuticals, agriculture, food, petrochemicals and environmental.