Gas-liquid Chromatographic Studies of Solution Processes PDF Download

Author: Richard John Sheehan
Publisher:
ISBN:
Category :
Languages : en
Pages : 602

View

Book Description

Author: Tibor Cserhati
Publisher: CRC Press
ISBN: 1000160114
Category : Science
Languages : en
Pages : 576

View

Book Description
oCompilation and evaluation of the newest applications of chromatography for food science and technology oEnumeration of chromatographic methods and critical discussion of results This book presents a unique collection of up-to-date chromatographic methods for the separation and quantitative determination of carbohydrates, lipids, proteins, peptides, amino acids, vitamins, aroma and flavor compounds in a wide variety of foods and food products. Chromatography in Food Science and Technology presents a concise evaluation of existing chromatographic methods used for many food and food product macro and microcomponents. Chromatographic methods are compiled according to the character of the food components to be separated. The book's chapters deal separately with the different classes of food components, presenting both gas and liquid chromatographic methods used for their determination, and discussing the advantages and disadvantages of each. Unlike other references, Chromatography in Food Science and Technology is entirely devoted to the use of chromatography for food analysis, and focuses on practical, food-related examples. It treats the theoretical aspects of chromatography briefly, to the degree that the information helps the use and development of new analytical methods for the separation of any kind of food components.

Author: James Bulmer Pattison
Publisher:
ISBN:
Category : Gas chromatography
Languages : en
Pages : 372

View

Book Description

Author: R.L. Grob
Publisher: Elsevier
ISBN: 0080858228
Category : Science
Languages : en
Pages : 255

View

Book Description
Environmental Problem Solving Using Gas and Liquid Chromatography

Author: G. Guiochon
Publisher: Elsevier
ISBN: 0080858473
Category : Science
Languages : en
Pages : 811

View

Book Description
Here is an invaluable new book on quantitative gas chromatography which explains how the method can - or should - be used for accurate and precise analysis. Gas chromatography is firmly established as one of the few major methods for the quantitative analysis of complex mixtures. It is fast, accurate and inexpensive, with a broad range of applications. It has however become very complex and involved: over 200 stationary phases, more than 10 detector principles and several very different column types are available from among the catalogs of over 100 manufacturers and major retailers. The progressive changes in the nature of gas chromatography have created new needs for information which are not satisfied by the literature presently available.This book provides a complete discussion of all the problems involved in the achievement of quantitative analysis by gas chromatography, whether in the research laboratory, in the routine analysis laboratory or in process control. For this reason the presentation of theoretical concepts has been limited to the essential, while extensive explanations have been devoted to the various steps involved in the derivation of precise and accurate data. This starts with the selection of the instrumentation and column, continues with the choice of optimum experimental conditions, then calibration and ends with the use of correct procedures for data acquisition and calculations. Finally, there is almost always a way to reduce errors and an entire chapter deals with this single issue. Numerous relevant examples are presented.The first part of the book presents the theoretical background, simple enough to be understood by all analytical chemists, but still complete and up-to-date. It discusses the problems of flow dynamics, retention and band broadening. The changes in band profile associated with column overloading are explained without much recourse to mathematics. The second part describes the gas chromatograph and discusses the properties of each of its parts: gas flow and pressure controller sampling system, oven, column switching valves, detectors. The different implementations, their advantages and drawbacks are discussed and compared. In addition, three chapters present packed column technology, open tubular column technology and some sophisticated new phase systems, respectively. The new phase systems described use adsorbents, modified by coating or grafting organic phase, and carrier gases containing vapors which are sorbed by the stationary phase and modify it, such as steam. The third part discusses the applications in qualitative and quantitative analysis. Calibration, peak integration, sources of errors arising from the various parts of the instrument as well as from the measurement process itself are carefully described in four detailed chapters. Methods to carry out accurate and precise analysis are presented. A last chapter is devoted to process control analysis and gives a number of detailed examples of applications. A lexicon explaining the most important chromatographic terms and a detailed index complete the book.This is a book which no chemical analyst should be without. It should be on the library shelf of all universities, instrument companies and any laboratory and plant where gas chromatography is used.

Author: Mortimer B. Lipsett
Publisher: Springer Science & Business Media
ISBN: 1468406914
Category : Science
Languages : en
Pages : 317

View

Book Description
During the past decade we have witnessed a revolution in analytical methods. The development of vapor phase chromatography for the separation and analysis of classes of substances ranging from metals and gases to a wide variety of organic materials has been one of the most exciting of these new techniques. Gas-liquid chromatography for the measurement of steroids is particularly significant for endocrinologists and reports during the past several years have demonstrated its usefulness. Because of the growing interest in this method, a committee of the Endocrinology Study Section composed of Drs. R. M. Dodson, Seymour Lieberman, Hilton A. Salhanick, and Ralph E. Peterson, felt that the time was propitious to hold this Workshop and it is on their behalf that I welcome you. We hope to obtain enough data during these sessions so that those attending this conference and those who may read the proceedings will be able to make an informed judgement about the usefulness of gas-liquid chromatography for the analysis of steroids in biological fluids. Thus, I hope that there will be adequate documentation of the reliability of the methods as well as a comparison of the advantages and disadvantages of this analytical method with other classical methods. If we can do this, this Workshop will provide a significant base of practical considerations about gas chromatographic analytic techniques. I would like to thank Drs. T. F. Gallagher, H. Wilson, H. Salhanick and L. Engel for agreeing to serve as Chairmen of the sessions.

Author: R. Stock
Publisher: Springer
ISBN: 1489933603
Category : Science
Languages : en
Pages : 392

View

Book Description
Classification of chromatographic methods Chromatography is the name given to a particular family of separation techniques of great effectiveness. The original method was described in 1903 by Tswett, who used it for the separation of coloured substances, and the name chromatog raphy stems from this. However, the limitation to coloured compounds never really obtained, and most chromatographic separations are nowadays performed on mixtures of colourless substances, including gases. Like fractional distillation, chromatography relies on the relative movement of two phases, but in chromatography one is fixed and is known as the stationary phase; the other is known as the mobile phase. Chromatographic methods may be classified first according to the nature of the mobile phase and, second, according to the nature of the stationary phase. The mobile phase may be a liquid or a gas, and the stationary phase may be a solid or a liquid. There are thus four main sub-divisions of the chromatographic process, as set out in Table 1.1. The system is called adsorption chromatography if the stationary phase is a solid, and partition chromatography if it is a liquid.

Author: Foujan Falaki
Publisher:
ISBN:
Category : Electronic books
Languages : en
Pages : 0

View

Book Description
In gas chromatography (GC), the sample is vaporized and injected onto the head of a chromatographic column. Elution is brought about by the flow of an inert gaseous mobile phase such as helium, argon, nitrogen, carbon dioxide, and hydrogen. In GC, the mobile phase does not interact with molecules of the analyte, and it only transports the analyte through the column. In two general kinds of GC, gas-solid chromatography (GSC) and gas-liquid chromatography (GLC), the mechanisms of analyte retention in the column are thoroughly different. In GLC, the analyte has been participated between a gaseous mobile phase and a liquid stationary phase. While in GSC, the retention of analytes is the consequence of its physical adsorption onto a solid stationary phase. In comparing of GLC and GSC, more widespread use of GLC has been found in all fields of science. This is mainly due to the semipermanent retention of active or polar molecules and the severe tailing of elution peaks, which is a consequence of the nonlinear character of adsorption process, in GSC. In GC, column efficiency requires that sample be of suitable size and be introduced as a plug of vapor. So, the sample preparation is a very important step in GC. The sample should be injected into a flash vaporizer port located at the head of the column, and its temperature is about 50°C above the boiling point of the least volatile component of the sample. So, the components of the sample should be easily vaporized in this temperature, and they should have high heat resistance not to be decomposed. Both of liquid and solid samples can be introduced to the column. But solid samples are ordinarily introduced as solutions or sealed into thin-walled vials that can be inserted at the head of the column and punctured or crushed from the outside. In order to separate and analyze the gaseous, liquid, and volatile solid samples directly, GC is a suitable analytical equipment. When the analyte sample is nonvolatile, the derivatization and pyrolysis GC techniques are crucial. Gas chromatography can be applied to the solution of many problems in various fields such as drugs and pharmaceuticals, environmental studies like air and clinical samples, petroleum industry, pesticides and their residues, and foods. On the other hand, most samples are not ready for direct introduction into instruments. For organics and volatile organics, the sample preparation procedures can be named as extraction, cleanup, derivatization, transfer to vapor phase, and concentration. So, the basic concept of a sample preparation method is to convert a real matrix into a sample in a format that is suitable for analysis by a separation or other analytical techniques. The goals of sample treatment step are as follows: (1) The capability of using smaller amounts of initial sample, especially for trace analysis. (2) Achieving higher specificity and selectivity in analytical determinations. (3) To improve the potential for automation or online methods and minimize the manual operations. (4) The usage of no or small volumes of organic solvents in order to approach the green chemistry techniques with less wastes and more friendly environment. On the other hand, different samples possess a variety of sample treatment methods, for example: (1) In order to treat solid samples and separate a purpose analyte, some enhanced solvent extraction methods include pressurized liquid extraction, microwave- and sonic wave-assisted extraction, supercritical fluid extraction, and superheated water extraction. (2) For analytes in solution, the sample preparation can be attributed to the analyte trapping methods such as -phase extraction, solid-phase microextraction, and stir bar extractions. (3) Also, the extraction of the analytes into a liquid phase can be achieved by other methods like membrane extraction, single-drop microextraction (SDME), and purge and trap. (4) For separation of analytes in the gas phase, trapping analytes from vapor samples and headspace analysis are used. As a result, sample preparation is not only a critical step but also possesses different ways to treat and convert matrix into a suitable sample to inject GC.

Author: A. Braithwaite
Publisher: Springer Science & Business Media
ISBN: 9401105995
Category : Science
Languages : en
Pages : 573

View

Book Description
This book provides a unified and balanced introduction to the general theory of chromatography, followed by a detailed treatment of the principles and practice of all the major techniques currently employed in the industrial and academic sectors. It is written as a broad introduction to the subject for mid to advanced undergraduates in chemistry, pharmacy, biochemistry, and is suitable for students following the now quite numerous Masters degrees in instrumental analysis. The book has been updated to incorporate advances of the last ten years, and it contains around 50% new or revised material.

Author: Elsa Lundanes
Publisher: John Wiley & Sons
ISBN: 3527675221
Category : Science
Languages : en
Pages : 228

View

Book Description
Finally a book on chromatography which is easy to grasp for undergraduates and technicians; covers the area in sufficient depth while still being concise. The book includes all recent technology advances and has core textbook features further improving the learning experience. This book is the perfect introduction into a methodology which is the underlying principle of the vast majority of separation methods worldwide. Everyone working in a lab environment must be familiar with the basis of these technologies and Tyge Greibrokk, Elsa Lundanes and Leon Reubsaet succeed in delivering a text which is easy to read for undergraduates and laboratory technicians, and covers the area in sufficient depth while still being concise. The book includes all recent technology advances and has core textbook features further improving the learning experience. Importantly, the text does not only cover all major modern chromatography technology (thin layer, gas, high pressure liquid, and supercritical fluid chromatography) but also related methods, in particular electrophoretic technologies.