A UPLC-MS/MS Method for Determination of Schaftoside in Rat Plasma and its Application to Pharmacokinetic Study

An accurate and validated ultra-performance liquid chromatography method with triple quadrupole mass spectrometer has been developed for the determination of schaftoside in rat plasma. Plasma samples were prepared by precipitating protein with acetonitrile. Schaftoside and quercetin (IS) were separated by a reversed-phase BEH C18 column (2.1 x 100 mm, 1.7 mu m, Waters, USA) kept at 40 degrees C. The mobile phase was consisted of acetonitrile and water (containing 0.1% formic acid) with gradient elution, pumped at a flow rate of 0.4 mL/min. The analytes were detected with positive electrospray ionization in multiple reaction monitoring (MRM) mode for target fragment ions m/z 563.06 -> 3.353.04 for schaftoside and m/z 301.12 -> 451.05 for IS. Good linearity for schaftoside was gained with a concentration range of 20-5000 ng/mL with a lower limit of quantification (LLOQ) of 20 ng/mL. Mean recovery of schaftoside from plasma were better than 77.7%. The intra- and inter-assay precisions were less than 5.0 and 11.6%, and the accuracy ranged from 91.9 to 106.6%. The method was successfully applied to a pharmacokinetic study of schaftoside after an intragastric administration of 2 mg/kg in rats.