Related Articles

Preparative Liquid Chromatography

This volume provides a straightforward approach to isolation and purification problems with a thorough presentation of preparative LC strategy including the interrelationship between the input and output of the instrumentation, while keeping to an application focus.

The book stresses the practical aspects of preparative scale separations from TLC isolations through various laboratory scale column separations to very large scale production. It also gives a thorough description of the performance parameters (e.g. throughput, separation quality, etc.) as a function of operational parameters (e.g. particle size, column size, solvent usage, etc.). Experts in the field have contributed a well balanced presentation of separation development strategies from preparative TLC to commercial preparative process with practical examples in a wide variety of application areas such as drugs, proteins, nucleotides, industrial extracts, organic chemicals, enantiomers, polymers, etc.

Journal of Chromatography Library, Volume 11: Liquid Chromatography Detectors

The renaissance of liquid chromatography took place in the late 1960’s and early 1970’s. The first edition of this book published in 1977 described the detectors that were available at that time and which provided a performance matching that of the contemporary equipment with which they were associated. It is interesting to note that the most popular detectors then (the UV detector, the refractometer detector, the fluorescence detector and the electrical conductivity detector) are still the most commonly used detectors nearly a decade later. Detector design, however, has changed very significantly over the intervening years. Modern high efficiency columns provide very narrow peaks and very fast separations, and thus the physical design of the detectors had to change to meet these new challenges. In 1977, there was little real understanding of the important role played by the detector in the overall function of the chromatographic system and although some of the factors were pointed out in the first edition of this book, in retrospect they appeared to be little understood. This second edition gives an entirely new presentation of the subject of liquid chromatography detectors.

Analytical Gas Chromatography 2nd Edition

Gas chromatography remains the world’s most widely used analytical technique, yet the expertise of a large proportion of chromatographers lies in other fields. Many users have little real knowledge of the variablesin the chromatographic process, the interaction between those variables, how they are best controlled, how the quality of their analytical results could be improved, and how analysis times can be shortened to facilitate the generation of a greater numberof more reliable results on the same equipment. An analyst with a more comprehensive understanding of chromatographic principles and practice, however, can often improve the quality of the data generated, reduce the analytical time, and forestall the needto purchase an additional chromatograph or another mass spectrometer.

The Second Edition of Analytical Gas Chromatography is extensively revised with selected areas expanded and many new explanations and figures. The section on sample injection has been updated to include newer concepts of split, splitless, hot and cold on-column, programmed temperature vaporization, and large volume injections. Coverage of stationary phases now includes discussion, applications, and rationale of the increased thermal and oxidative resistance of the newly designed silarylenepolysiloxane polymers. Conventional and”extended range”polyethylene glycol stationary phases are examined from the viewpoints of temperature range and retention index reliabilities, and the chapter on”Variables”has been completely rewritten. The ways in which carrier gas velocity influences chromatographic performance is considered in detail, and includes what may be the first rational explanation of the seemingly anomalous effects that temperature exercises on gas viscosity (and gas flow). The practical effects that these changes cause to the chromatography is examined in pressure-, flow-, and”EPC-“regulated systems.”Column Selection, Installation, and Use”has been completely rewritten as well. The accuracy of theVan Deemter plots has been greatly enhanced; a new program corrects for the first time for the changes in gas density and diffusion that occur during the chromatographic process because of solute progression through the pressure drop of the column. A new section has also been added on meeting thespecial requirements of columns destined for mass spectral analysis. The chapter on”Special Applications”has been expanded to include considerations of”selectivity tuning,”of fast analysis, and the section of Applications has been thoroughly updated and expanded.

Incorporates nearly 60% new material
Covers the newest concepts and materials for sample injection and stationary phases
Presents detailed consideration of the influence of carrier gas velocity on practical aspects of chromatographic performance
Contains a chapter on “Special Analytical Techniques” which includes consideration of selectivity tuning and fast analysis
Provides a new section addressing the special requirements of columns to be used in mass spectral analysis
Includes an improved program that greatly enhances the accuracy of the Van Deemter plots by more accurately depicting localized chromatographic conditions at each point in the column

R.J.W Scott-liquid chromatography detectors

A chromatography detector is a device used in gas chromatography (GC) or liquid chromatography (LC) to detect components of the mixture being eluted off the chromatography column. There are two general types of detectors: destructive and non-destructive. The destructive detectors perform continuous transformation of the column effluent (burning, evaporation or mixing with reagents) with subsequent measurement of some physical property of the resulting material (plasma, aerosol or reaction mixture). The non-destructive detectors are directly measuring some property of the column eluent (for example UV absorption) and thus affords greater analyte recovery.