Monitoring the metabolism of moexipril to moexiprilat using high-performance liquid chromatography-electrospray ionization mass spectrometry.

High-performance liquid chromatography combined with a UV absorbance detector and electrospray ionization mass spectrometer is used for the simultaneous analysis of moexipril and moexiprilat in biological samples. Moexipril and moexiprilat are determined in samples metabolized by rat and human liver microsomal preparations, and also in rat urine. The calibration curve is linear in the ng/mL and microg/mL concentration range of the injected moexipril.