No “recipes” are given for specific analyte methods; these are plentiful in the scientific literature. The intention has been to prepare the reader to examine critically the published methods and to be aware of the major pitfalls in designing and implementing an analytical procedure. The first five chapters describe the operation of a mass spectrometer system and its use for qualitative and quantitative analysis while the final chapters describe some successful examples of application and explain how the methods chosen were designed to improve sensitivity, specificity and speed of analyses. Possible future applications are also discussed. A list of acronyms and a short section on the meaning of common terms is included at the end of the volume. Links to references, web sites and other useful information are included.