Determination of Amisulpride in Plasma by LC-MS/MS

OBJECTIVE To establish an LC-MS/MS method for the determination of amisulpride in human plasma. METHODS The sample extraction was performed by ethyl acetate-dichloromethane(4∶1). Separation was achieved on a Welch Materials XB-C18(2.1 mm×150 mm，3 μm) column with the mobile phase consisted of methanol-water with 5 mmol·L-1 ammonium formate (95:5). An Agilent 6410 triple quad mass spectrometer system equipped with an electrospray ionization ion-trap source was used as the detector and operated in the positive ion mode. Selected reaction monitoring(SRM) was used as the precursor to product ion combinations of m/z 370.3→242.1 and m/z 324.2→112.1 to detect amisulpride and the internal standard, respectively. The method was used to evaluate clinical application for 10 healthy volunteer after oral dose of 200 mg amisulpride tablet. RESULTS The average recoveries for amisulpride were 104.44%，104.74% and 95.65%，respectively. The method was accurate with intra-day(n=5) and inter-day (n=3) RSD within 15%. The calibration curves for amisulpride had good linearity, over the concentration range of 0.5-500 μg·L-1. The limits of quantitation for amisulpride was 0.52 μg·L-1. CONCLUSION The method provides a sensitive, accurate, precise and reliable analytical procedure for clinical monitoring of amisulpride plasma and its phamacokinetic studies.