John W. Dolan – författare

Gradient elution demystified Of the various ways in which chromatography is applied today, few have been as misunderstood as the technique of gradient elution, which presents many challenges compared to isocratic separation. When properly explained, however, gradient elution can be less difficult to understand and much easier to use than often assumed. Written by two well-known authorities in liquid chromatography, High-Performance Gradient Elution: The Practical Application of the Linear-Solvent-Strength Model takes the mystery out of the practice of gradient elution and helps remove barriers to the practical application of this important separation technique. The book presents a systematic approach to the current understanding of gradient elution, describing theory, methodology, and applications across many of the fields that use liquid chromatography as a primary analytical tool. This up-to-date, practical, and comprehensive treatment of gradient elution: * Provides specific, step-by-step recommendations for developing a gradient separation for any sample * Describes the best approach for troubleshooting problems with gradient methods * Guides the reader on the equipment used for gradient elution * Lists which conditions should be varied first during method development, and explains how to interpret scouting gradients * Explains how to avoid problems in transferring gradient methods With a focus on the use of linear solvent strength (LSS) theory for predicting gradient LC behavior and separations by reversed-phase HPLC, High-Performance Gradient Elution gives every chromatographer access to this useful tool.

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 conditionsEquipment and detectionThe column—the "heart" of the HPLC systemReversed-phase separation, normal-phase chromatography, gradient elution, two-dimensional separation, and other techniquesComputer simulation, qualitative and quantitative analysis, and method validation and quality controlThe separation of large molecules, including both biological and synthetic polymersChiral separations, preparative separations, and sample preparationSystematic development of HPLC separations—new to this editionTroubleshooting tricks, techniques, and case studies for both equipment and chromatogramsDesigned 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.

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.

Gradient elution demystified Of the various ways in which chromatography is applied today, few have been as misunderstood as the technique of gradient elution, which presents many challenges compared to isocratic separation. When properly explained, however, gradient elution can be less difficult to understand and much easier to use than often assumed. Written by two well-known authorities in liquid chromatography, High-Performance Gradient Elution: The Practical Application of the Linear-Solvent-Strength Model takes the mystery out of the practice of gradient elution and helps remove barriers to the practical application of this important separation technique. The book presents a systematic approach to the current understanding of gradient elution, describing theory, methodology, and applications across many of the fields that use liquid chromatography as a primary analytical tool. This up-to-date, practical, and comprehensive treatment of gradient elution:* Provides specific, step-by-step recommendations for developing a gradient separation for any sample* Describes the best approach for troubleshooting problems with gradient methods* Guides the reader on the equipment used for gradient elution* Lists which conditions should be varied first during method development, and explains how to interpret scouting gradients* Explains how to avoid problems in transferring gradient methods With a focus on the use of linear solvent strength (LSS) theory for predicting gradient LC behavior and separations by reversed-phase HPLC, High-Performance Gradient Elution gives every chromatographer access to this useful tool.

Over the last 15 years, high-performance liquid chromatogra­ phy (LC) has made the transition from an instrument used only by experts in research labs to a tool used for routine applications by relatively unskilled workers. With this transition have come in instrumentation and column technology. In major advances the past, the operator had to be a jack-of-all-trades, with a screw­ driver, soldering iron, and various wrenches as constant compan­ ions in the LC lab. Today, many instruments contain micropro­ cessors as powerful as those of mainframe computers of earlier days. With this technology has come a variety of self-diagnostic tools that allow the LC system to locate many of its own prob­ lems. Traditionally, well-honed LC troubleshooting skills have been a result of years of work at the bench. Today the LC system itself often can do a better job of troubleshooting than the operator can. Yet many of the problems of the past are still the major problems of today: air bubbles, check valves, detector lamps, and, of course, problems with the separation. An added pressure on the operator of today's LC system is that of productivity-the lab often cannot afford unnecessary downtime. This means that the operator has to be a troubleshooting expert, or has to have that expertise at his or her fingertips. The present book was written to provide this expertise in an easy-to-use format for users at all levels of experience.

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.

Over the last 15 years, high-performance liquid chromatogra­ phy (LC) has made the transition from an instrument used only by experts in research labs to a tool used for routine applications by relatively unskilled workers. With this transition have come in instrumentation and column technology. In major advances the past, the operator had to be a jack-of-all-trades, with a screw­ driver, soldering iron, and various wrenches as constant compan­ ions in the LC lab. Today, many instruments contain micropro­ cessors as powerful as those of mainframe computers of earlier days. With this technology has come a variety of self-diagnostic tools that allow the LC system to locate many of its own prob­ lems. Traditionally, well-honed LC troubleshooting skills have been a result of years of work at the bench. Today the LC system itself often can do a better job of troubleshooting than the operator can. Yet many of the problems of the past are still the major problems of today: air bubbles, check valves, detector lamps, and, of course, problems with the separation. An added pressure on the operator of today's LC system is that of productivity-the lab often cannot afford unnecessary downtime. This means that the operator has to be a troubleshooting expert, or has to have that expertise at his or her fingertips. The present book was written to provide this expertise in an easy-to-use format for users at all levels of experience.