Separation Methods in Organic Chemistry and Biochemistry [antikvár]

Preface The isolation of pure substance is frequently the major laboratory effort required for the solution of a chemical or biochemical problem. This may require considerable time and effort. At any point in the solution of an isolation problem more than one method or combination of methods can usually be employed. The choice of the most rapid and convenient procedure requires careful evaluation of many factors which include the available equipment, the time and assay facilities required for a particular step, use of previous knowledge or experience, and the scale of operation. A major objective of this book is to provide perspectives for the commonly used methods and indications for their use. The determination of molecular properties useful in separation based on micro test methods, paper chromatography, thin-layer chromatography, and electrophoresis is described. Illustrative examples of each method are included. Separations are classed generally as group or fractionation methods depending on the selectivity or fractionation needed. The theoretical principles of group-separation procedures, liquid-liquid partition, ion-exchange selectivity, gel permeation, and adsorption are included. Methods of influencing the selectivity coefficients are discussed. The basic theory of fractionation methods is developed and the principles of application are discussed in terms useful to practicing chemists whose major interest is the use of separation methods to accomplish a given objective and not separation per se. It is hoped that the book will serve as a useful guide to the solution of many practical problems encountered in the laboratory practice of organic chemistry and biochemistry. I am indebted to many co-workers in the Merck Sharp & Dohme Research Laboratories who have offered many helpful suggestions during the preparation of the manuscript, especially L. Chaiet, R. G. Denkewalter, T. E. Jacob, E. A. Kaczka, A. J. Kempf, T. W. Miller, H. Shafer, and R. Weston. The