Use of Nano-Electrospray for Metabolite Identification and QuantitativeAbsorption, Distribution, Metabolism and Excretion Studies

Determination of the pharmacokinetics and metabolite identification have been an integral part of drug discov-ery and development to ensure that drugs have appropriate absorption, distribution, metabolism and excretion properties.Liquid chromatography interfaced with a mass spectrometer has greatly facilitated these studies. Nano-electrospray hasdistinct sensitivity advantages and the increased amount of time available to perform mass spectrometric experiments fa-cilitates structural characterization of metabolites. The recently developed silicon chip-based nano-electrospray devicesare more practical than pulled capillaries. The use of these devices for the determination of pharmacokinetics and metabo-lite identification will be described and particular attention will be paid to the distinct advantages and disadvantages thesedevices offer.