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 latest edition of the authoritative reference to HPLC High-performance liquid chromatography (HPLC) is today the leading technique for chemical analysis and related applications, with an ability to separate, analyze, and/or purify virtually any sample. Snyder and Kirkland's Introduction to Modern Liquid Chromatography has long represented the premier reference to HPLC. This Third Edition, with John Dolan as added coauthor, addresses important improvements in columns and equipment, as well as major advances in our understanding of HPLC separation, our ability to solve problems that were troublesome in the past, and the application of HPLC for new kinds of samples. This carefully considered Third Edition maintains the strengths of the previous edition while significantly modifying its organization in light of recent research and experience. The text begins by introducing the reader to HPLC, its use in relation to other modern separation techniques, and its history, then leads into such specific topics as: The basis of HPLC separation and the general effects of different experimental conditions Equipment and detection The column—the "heart" of the HPLC system Reversed-phase separation, normal-phase chromatography, gradient elution, two-dimensional separation, and other techniques Computer simulation, qualitative and quantitative analysis, and method validation and quality control The separation of large molecules, including both biological and synthetic polymers Chiral separations, preparative separations, and sample preparation Systematic development of HPLC separations—new to this edition Troubleshooting tricks, techniques, and case studies for both equipment and chromatograms Designed to fulfill the needs of the full range of HPLC users, from novices to experts, Introduction to Modern Liquid Chromatography, Third Edition offers the most up-to-date, comprehensive, and accessible survey of HPLC methods and applications available.

High-Performance Liquid Chromatography: Advances and Perspectives, Volume 1 deals with the fundamental aspects of high-performance liquid chromatography, a technique used in chemical analysis. The publication provides accounts, presented by experts in the field, of a variety of topics in high-performance liquid chromatography. Each chapter covers interesting subjects such as the evolution of liquid chromatography; the use of bonded phases in high-performance chromatography; effects of ionization and complex formation on retention and selectivity in reversed-phase chromatography; and gradient elution. Chromatographers, chemists, and researchers in the field of chemical analysis will find this book a valuable reference material.

Many solvents can be used to prepare mobile phases in liquid chromatography. Also, mixtures of solvents at different ratios are used to modify the mobile phase properties. This can make solvent selection for method development a hard task, unless suitable guidelines are followed. This chapter summarizes the most common strategies used by skilled chromatographists in reversed-phase, normal-phase, and hydrophilic interaction liquid chromatography. These are based on considerations about the global polarity of solutes, stationary phase and mobile phase, which determine the elution strength, and on the particular profile of the contributions of intermolecular interactions to the global polarity, which determines the selectivity. The optimization of selectivity using isoeluotropic mixtures on the rational basis provided by solvent selectivity triangles and systematic trial-and-error procedures in the isocratic and gradient elution modes is described. Additional considerations for mobile-phase selection, including computer-assisted interpretive optimization, sustainability criteria, and the use of high temperatures, are also commented.

High performance liquid chromatography (HPLC) has long been recognized as one of the most useful and versatile analytical techniques. It has now progressed from being a highly expensive method of analysis to a routine technique with wide applications. Consequently there is a requirement in many chemistry and chemistry-related courses for students to acquire a detailed understanding of the principles and practice of HPLC. Written in a manner suitable for undergraduate students studying analytical chemistry and learning about chromatographic analytical techniques applied to pharmaceutical analysis, biochemistry and related disciplines, High-performance Liquid Chromatography: Fundamental Principles and Practice introduces the fundamentals of HPLC. Loosely structured in three parts, the text begins with a thorough introduction of the subject and then progresses through the essential knowledge of the instrumentation needed for HPLC. The final part covers with the applications of HPLC in real-world situations. Developed by a team of international experts from a wide cross-section of disciplines, the text is relevant to a wide range of courses.

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.