Investigation of the metabolic fate of the neuroleptic drug haloperidol by capillary electrophoresis-electrospray ionization mass spectrometry.

Combined capillary electrophoresis-mass spectrometry (CE-MS) is a powerful analytical tool for the characterization of components of complex mixtures. Furthermore, when interfaced with an electrospray ionization (ESI) source, skimmer induced fragmentation can yield structural information that aids compound identification. We show that these techniques can be used to probe the metabolic fate of drugs by investigation of the phase I metabolism of the widely used neuroleptic drug haloperidol. In addition, we demonstrate differences of in vitro metabolism of haloperidol by mouse and guinea pig hepatic microsomes.