As new techniques of transferring from liquid to gas phase and measuring masses of drug molecules and metabolites become more prevalent, so do the technical challenges of putting these techniques into proper use, as well as the task of consolidating emerging applications. "Identification and Quantification of Drugs, Metabolites and Metabolizing Enzymes by LC-MS, Volume 6" fills the gap in the lack of presently available literature by providing a critical review in the current use of liquid chromatography-mass spectrometry (LC-MS) in drug discovery and development. With chapters written by experts with a wide range of practical experience from the pharmaceutical industry, emphasis is placed on techniques and applications.The book also includes chapters on how to utilize LC-MS instrumentation for current drug metabolism problems. This book is intended for those beginning to use LC-MS for drug metabolism studies as well as for those considered advanced practitioners. It introduces readers to the practical applications of modern liquid chromatography-mass spectrometry (LC-MS) in a wide range of drug metabolism studies. It provides a comprehensive description of different forms of metabolites, with detailed discussion on the wide range of methodologies used to identify them. It highlights problems associated with drug quantification and offers practical solutions.