Rapid ultraperformance liquid chromatography-tandem mass spectrometry method for quantification of oxcarbazepine and its metabolite in human plasma

A rapid and sensitive ultraperformance liquid chromatography tandem mass spectrometry assay was developed for the simultaneous analysis of oxcarbazepine and its main metabolite in human plasma. The assay involves a simple solid-phase extraction procedure of 0.3 mL of human plasma and analysis was performed on a triple-quadrupole tandem mass spectrometer in multiple reaction monitoring mode via electrospray ionization. Separation was achieved on an Acquity UPLC (TM) BEH C(18) column (50 x 2.1 mm, i.d., 1.7 mu m) with isocratic elution at a flow-rate of 0.25 mL/min and imipramine was used as the internal standard. The standard calibration curve was linear over the range 9.580-5070.205 ng/mL for oxcarbazepine (OXC) and 19.444-10290.800 ng/mL for 10,11-dihydro-10-hydroxycarbamazepine (MHD), expressed by the linear correlation coefficient r(2), which was better than 0.995 for OXC and MHD. The intra-and inter-day precision and accuracy of the quality control samples were within 10.0%. The recoveries were 81.0, 89.6 and 66.6% for OXC, MHD and imipramine, respectively. The total run time was 1.5 min only for each sample, which makes it possible to analyze more than 350 samples per day. Copyright (C) 2010 John Wiley & Sons, Ltd.