Rapid Determination of a New Angiotensin-Converting Enzyme Inhibitor, Imidapril, and Its Active Metabolite in Human Plasma by Negative-Ion Desorption Chemical Ionization-Tandem Mass Spectrometry (MS/MS)

Abstract

A very rapid and highly sensitive method using desorption chemical ionization (DCI)-tandem mass spectrometry (MS/MS) with selected reaction monitoring is reported for the simultaneous determination of imidapril and its active metabolite (M1) in human plasma. Imidapril and M1 in plasma were extracted by a C₁₈ solid phase exraction cartridge after deproteinization, and derivatized with pentafluorobenzyl bromide. One μl of prepared sample was applied to the DCI filament and analyzed by DCI/MS/MS within a few minutes. The limits of determination of imidapril and M1 were 0.2 and 0.5 ng/ml in human plasma, respectively. The features of this method make it appropriate for use in pharmacokinetic studies with human plasma after oral administration of imidapril.