This book details all of the relevant information on the fragmentation of drugs and pesticides. It extends this information by the interpretation of series of mass spectra in available mass spectral library collections for liquid chromatography ?tandem mass spectrometry (LCSS). The information provided indicates important fragmentation pathways in the various chemical compound classes. Whenever available or useful, fragmentation in both positive-ion and negative-ion mode is discussed and compared. This is important since no complete databases about the fragmentation of these substances are available, and the information on to interpreting unknown fragments is scattered. Thus, this book will provide important information on how to interpret spectra so that fragments can be correctly identified that are not contained in a database. Important classes of compounds discussed include pesticides and related compounds as well as drugs for cardiovascular diseases and hypertension, psychotropic or psychoactive drugs, drugs related to digestion and the gastrointestinal tract, antimicrobial compounds, and other classes of drugs, such as steroids, drugs of abuse.