ENANTIOSPECIFIC DETERMINATION OF NIMODIPINE IN HUMAN PLASMA BY LIQUID CHROMATOGRAPHY TANDEM MASS SPECTROMETRY

摘要

A direct enantiospecific HPLC assay using tandem mass spectrometric (MS-MS) detection via pneumatically-assisted electrospray has been developed for the determination of the calcium antagonist nimodipine in human plasma. By the addition of ammonium acetate (2 mM) to the purely organic eluent ethanol-n-heptane (20:80, v/v) charged species (M + NH4+) were producible by electrospray ionization at sufficient sensitivity. Routine determination of nimodipine enantiomers in human plasma in the working range of 0.5-75 mu g/l plasma for each isomer with an accuracy less than or equal to+/-10% and a precision of about 10% (20% close to the limit of quantification) was possible. This was comparable to the available LC-GC-MS assay, however, the time required for routine analysis of ca. 150 unknowns could be reduced from 4 weeks to 1 week. [References: 10]