Lokesh Bhattacharyya and Jeffrey S. Rohrer (Eds): Applications of Ion Chromatography for Pharmaceutical and Biological Products

Abstract

Ion chromatography revolutionized the analysis of small inorganic ions by replacing tedious individual gravimetric and titration methods with a single automated process, capable of analysing a number of ions simultaneously. Today the range of potential applications has grown to include a wider range of ionic and ionizable materials such as biopolymers. This book focuses on a segment of those applications arising from the use of ion chromatography in the pharmaceutical industry, and does so very well. The book is a little gem, and those readers attracted to the book by its title will find that it delivers exactly what it promises. The book contains 24 chapters under four general section headings with an appendix containing acid dissociation constants for compounds of pharmaceutical interest. Part I describes instrumentation, retention mechanisms, and operating principles in five chapters. These are quite general and useful to novice and more experienced chromatographers alike. There is a good discussion of ion exchange and ion exclusion mechanisms, modelling and method development, and instrumentation (focused on the design of ion suppressors and the pulsed electrochemical detector). The pulsed electrochemical detector is discussed further in later chapters, particularly its applications in biotechnology, where it has played a major role in the expansion of ion chromatography from its origins. Later chapters also discuss the use of the charged aerosol detector and mass spectrometry for the detection and identification of compounds difficult to determine by conductivity and electrochemical methods. These are novel detection methods at present, but have the potential to play a significant role in the development of ion chromatography for the analysis of unconventional samples. The coupling of ion chromatography to mass spectrometry (electrospray ionization of the desalted eluent) tackles the problem of how to identify compounds for which standards are not available, particularly impurities in high molecular weight biopolymers or the totally unexpected compound in a chromatogram. Part II covers pharmaceutical applications in 11 chapters. As well as the expected identification of small anions and cations used in drug formulations, the analysis of aminoglycoside antibiotics and cholinergic compounds is described. About half of all drugs are formulated as salts so the assay of active ingredients and excipients, determination of impurity profiles, identification of contaminants, and forensic source identity of raw materials can be performed by ion chromatography. This section also contains chapters on sample preparation, validation and pharmacopeial methods. The chapters are copiously illustrated with chromatograms, appreciated by this old chromatographer. There is also a focus on regulatory issues of interest to those who work according to the dictates of good laboratory practice. Part III covers biotechnology applications in five chapters. Topics covered include glycan, monosaccharide, oligosaccharide, glycoprotein, amino acid, and carbohydrate C. F. Poole (&) Wayne State University, Detroit, MI, USA e-mail: cfp@chem.wayne.edu