High-performance liquid chromatography-electrospray ionization mass spectrometry method for the measurement of moclobemide and two metabolites in plasma

A rapid and sensitive liquid chromatography-electrospray ionisation mass sp ectrometry (HPLC-ESI-MS) assay has been developed for the measurement of mo clobemide and metabolites, Ro12-5637 and Ro12-8095, in human plasma. Sample preparation (0.5 ml plasma) involves solid-phase extraction using C-18 car tridges. A Nova-Pak phenyl column (Waters, 4 mum, 150X2 mm I.D.) was employ ed for analyte separation with a mixture of 0.2 M ammonium formate buffer, pH 3.57 and acetonitrile as the mobile phase. The within- and bstween-day p recisions of the assay were <18% and the limit of quantification for all an alytes was 0.01 <mu>g/ml. The total run-time was 6 min. The method describe d was used to measure moclobemide, Ro12-5637 and Ro12-8095 in human plasma following an oral 300 mg dose. (C) 2001 Elsevier Science B.V. All rights re served.