Gas-Adsorption Chromatography

Gas-Adsorption Chromatography

Gas-Adsorption Chromatography Andrei v. Kiselev and Yakov I. Yashin Department 0/ Chemistry, Moscow University and Institute 0/ Physical Chemistry, Academy 0/ Sciences 0/ the USSR Translated from Russian oy J. E. S. Bradley Senior Lecturer in Physics, University 0/ London c:t? Springer Science+Business Media, LLC 1969

Professor Andrei Vladimirovich Kiselev is the director of the Laboratory of Adsorption and Gas Chromatography, Department of Chemistry, Moscow University, and also of the Laboratory of Surface Chemistry, Institute of Physical Chemistry, Academy of Sciences of the USSR. He was born in 1908; in 1938 he attained the degree of candidate and in 1950 the degree of doctor of chemieal sciences. He has published over 500 papers on the surface chemistry of solids, the synthesis and structure of adsorbents, the theory of molecular interaction in adsorption and chromatography, thermodynamics of adsorption, calorimetric measurements of heats of adsorption, and adsorption from solution. Yakov Ivanovich Yashin is the director of the gas chromatography division of an experimental automatie equipment design organization. Born in 1936, he graduated from the chemical factilty at Gor'kii University in 1958 and attained the degree of candida te of chemical sciences in 1965. Since 1959 he has worked in the area of gas chromatography, since 1961 in collaboration with Professor Kiselev. He has published over 50 papers on the geometrieal structure and chemical nature of adsorbent surfaces, on molecular interactions as studied by gas chromatography, on applications of gas chromatography in analysis and in physical chemistry, and on the design of laboratory chromatographs. Library of Congress Catalog Card Number 69-12531 The original Russian text, published for the Institute of Physical Chemistry of the Academy of Sciences of the USSR by Nauka Press in Moscow in 1967 as part of a series on the Chemistry of Surfaces and Adsorption, has been corrected by the authors for the English edition. AH8peü B.aaaU~f,Up06U" R u c e.a e 6, Hn06 H6alt06U'I/ H 11.1. U 1t ra30-aacop6~hobilajl xpoma TOrpatlJHJI GAZO ADSORBTSIONNA YA KHROMA TOGRAFIYA GAS-ADSORPTION CHROMATOGRAPHY 1969 Springer Science+-Business Media New York Originally published by Plenum Press, New York in 1969. United Kingdom edition published by Plenum Press, London A Division of Plenum Publishing Company, Ltd. Donington House, 30 Norfolk Street, London W. C. 2, England All righ ts reserved No part of this publication may be reproduced in any form without written permission from the publisher ISBN 978-1-4899-6238-6 ISBN 978-1-4899-6503-5 (ebook) DOI 10.1007/978-1-4899-6503-5 Softcover reprint ofthe hardcover 1st edition 1969

Foreword One of the present authors in eollabol'ation with his eolleagues has undertaken the eompilation of aseries of books on adsorption and the ehemistry of solid surfaees, beeause this area has reeently developed so rapidly that it is no longer possible to deal with it in detail in one volume. This is the more important beeause this area has beeome importaht in chemical technology and in many aspeets of research in chemistry, bioehemistry, and elsewhere. The objeet in this series is not to give an exhaustive exposition of alliines of work or to survey all publications; the books will rather deal mainly with those areas in surfaee chemistry and adsorption in which the authors have direct praetieal experienee. The pl'esent volume dea:ls with gas-adsorption chromatography. Moleeular chromatography, especially gas ehromatography, would appear one of the most promising areas, sinee gas ehromatography has be co me one of the principal instrumental methods of analysis in many branches of industry and research. The simple physicochemical basis (differenees in molecular interaetions of the components in solution or adsorption) makes the method universal; it is also highly effective for complex mixtures of organic and inorganic substances of boiling point up to 600 C. Rapid automatie analysis is possible, with ionization detectors of high sensitivity, while the apparatus is simple and may be standardized. Automation for many chemical processes is often based on gas ehromatography, as well as routine plant analyses. The rapid development of gas chromatography followed the discovery by Martin and James of gas-liquid chromatography 15 years ago, and the pace of development is continually quickening. The current annual output of original papers on gas chromatography v

vi FOREWORD is in excess of 2000. The method is now often applied to mixtures that could not be analyzed by other methods. Development gas-adsorption and gas-liquid forms of the method are the main ones used in analysis; but the usual highly active adsorbents of high specific surface are suitable only for separating highly volatile substances, whereas far less volatile substances are separated in gas -liquid chromatography. The latter is therefore the more widely used. Most books on gas chromatography deal mainly with gasliquid chromatography, as in Keuleman's (1959) Gas Chromatography, Zhukhovitskii and Turkel'taub's (1962) Gas Chromatography, and Nogare and Juvet's (1966) Gas-Liquid Chromatography. However, various deficiences in this method have become apparent with the increase in sensitivity of detectors and with the extension of applications, in particular the volatility and instability of liquid phases at high column temperatures. Recently there have been advances in the synthesis and modification of solid adsorbents with uniform surfaces having a variety of compositions, which has increased the interest in gas-adsorption chromatography. Unfortunately, the papers on this are scattered over a variety of journals and are often inaccessible. One objective of this book is to overcome this difficulty. Gas chromatography is still in the stage of empirical selection,. so we have considered it important here to deal with gas-adsorption chromatography from a unified standpoint based on mole cular interactions in adsorption. It is assumed that the reader is familiar with the general theory and apparatus of gas chromatography; these are adequately dealt with in the books mentioned above, and also in Schay's (1963) Theoretical Principles of Gas Chromatography. The first chapter of this book deals with the gas-adsorption and gas-liquid forms, with emphasis on their advantages and disadvantages, ways of overcoming the disadvantages, ways of utilizing the methods, and areas of application. The second chapter uses the theory of molecular interaction in adsorption to consider the effects of surface chemistry and of molecular structure on gaschromatographic separation. In that chapter a classification of compounds and sorbents is given on the basis of these features,

FOREWORD vii with a statement of the best uses of nonspecific and specific adsorbents of various types. The third chapter deals in detail with the effects of surface geometry, porosity, and granularity on the separation. The fourth chapter deals with the use of gas-adsorption chromatography in physicochemical studies of adsorption and in the determination of specific surface. The fifth chapter surveys in detail the analytical applications, starting with the separation of hydrogen isomers and isotopes and extending to the analysis of heavy polynuc1ear aromatic compounds with boiling points up to 600 C. One seetion of this chapter compares gas-adsorption and gas-liquid methods on the same mixtures. The sixth chapter gives practical techniques for the preparation of adsorbents and adsorption columns. The book does not deal with the dynamics of gas-adsorption columns. Rachinskii (1964) in Introduction to the General Theory of Sorption Dynamics in Chromatography gives a general treatment of this; Giddings (Dynamics of Chromatography, Vol. 1, Marcel Dekker, Inc., New York, 1965) deals with it in detail. Timofeev (1962) deals with the aspects of adsorption kinetics important to gas-adsorption chromatography in his Adsorption Kinetics. There seems little doubt that the next few years will see a rapid development of the molecular chromatography of liquid solutions without conversion to vapor, with the use of high-sensitivity methods of detection. This is essential to the chromatographie analysis of complicated and thermally unstable molecules, especially macromolecules, since these are of especial importance to biochemistry and polymer chemistry. Here molecular adsorption from solution onto solid adsorbents will play an important part. However, this topic falls outside the scope of this book, and it is hoped to deal with it separately. The book is intended for general use in plant laboratories and research institutes, as wen as for specialists in adsorption, molecular chromatography, and molecular interactions. It is also of value to graduate students and those specializing in areas of adsorption, chromatography, and analytical, preparative, and industrial applications of gas chromatography The listing of literature on gas-adsorption chromatography is fairly exhaustive (up to 1966); but this is a difficult task in this rapidly developing field, so it may weil be that some papers have

viii FOREWORD been overlooked. We shall be glad to receive notice of such papers and of any other deficiencies in the book. In the English edition the authors have made several additions to the text which partly cover the recent literature. We wish to record our thanks to A. P. Arkhipova, A. G. Bezus, T. I. Goryunova, T. S. Kiseleva, R. S. Petrova, and V. L. Yashina for assistance in preparing the manuscript for publication. A. V. Kiselev and Ya. I. Yashin

Contents CHAPTER 1. Introduction. Advantages and Disadvantages of Gas-Adsorption Chromatography and Gas- Liquid Chromatography... Literature Cited.............. CHAPTER II. Role of the Surface Chemistry of Adsorbents and Nature of Molecular Interactions................... Nonspecific and specific molecular interactions Classification of molecules and adsorbents by character of molecular interaction. Type ladsorbents. Type II adsorbents............ Type III adsorbents.... Comparison of adsorbent types I, II, and III. Literature Cited....................... CHAPTER III. Role of the Geometrical Structure of Adsorbents.... 68 The general relation between the performance of a column and the geometrical structure of the adsorbent.... 68 Classification of adsorbents by geometrical structure................. 69 Geometrical modification of adsorbents... 70 Production of porous polymers........ 72 Structure of adsorbent pores and retention of materials................. 74 Structure of adsorbent pores and band broadening. 80 1 6 10 10 11 16 40 52 56 61 ix

x CONTENTS Immobile supports for gas ehromatography... Literature Cited.... CHAPTER IV. Gas-Chromatographie Determination of Adsorption and Speeific Surface for Solids 104 Physicoehemical applications of gas ehromatography............... 104 Derivation of the equilibrium adsorption isotherm from an equilibrium chromatogram...... 105 Gas-chromatographie determination of free energies and of heats and entropies of adsorption.... 120 Gas-chromatographie determination of the energies of hydrogen bonds between adsorbate moleeules..................... 134 Gas-chromatographie determination of speeific surface..................... 136 Application of gas chromatography to adsorption kinetics. 140 Literature Cited...................... 141 CHAPTER V. Analytical Use of Gas-Adsorption Chromatography.................. 146 Analysis of hydrogen isotopes and isomers 146 Analysis of inorganic gases and methane. 149 Analysis of hydrocarbon gases......... 159 Analysis of liquid mixtures........... 172 Analysis of high-boiling liquids and of solids 204 Aspects of identification and quantitative estimation. 211 Comparison of gas-adsorption and gas-liquid methods for identical mixtures 216 Literature Cited.............. 220 CHAPTER VI. Praetical Techniques 229 Preparation of adsorbents for gas chromatography. 229 Preparation of eapillary adsorption columns... 241 Drying and purification of the carrier gas..... 244 Determination of exit time of an unadsorbed gas with an ionization deteetor 245 Literature Cited. 247 Index....... 251 90 98