Use of LC-MS/MS for xenobiotic metabolism studies in animals

The use of LC-MS/MS in the identification of xenobiotic metabolism pathways in animals is described, on the basis of selected examples in the field of toxicologically relevant growth promoting agents.The structural elucidation of xenobiotic metabolites in complex biological matrices is achieved using various analytical methods and strategies using LC-MS with ESI or APCI ionisation techniques in combination with in-source CAD or MS/MS experiments.The use of some particular analytical tools (e.g.H/D exchange or MS n multisequential experiments) for solving specific structural ambiguities is also discussed.