Objective: An sensitive and selective liquid chromatography-tandem mass spectrometry (LC-MS-MS) method was developed and validated for the determination of oxyresveratrol in rat bile. Method: The analyte and the internal standard (carbamazepine) were extracted from bile samples using simple liquid-liquid extraction technique with ethyl acetate

seperated on a ZORBAX SB-C18 column (2.1 mm×50 mm

1.8 μm) with mobile phase of acetonitrile and water containing 0.2% formic acid.Detected by triple quadruple mass spectrometry with an positive electrosprayionization interface

and quantified using multiple reaction monitoring (MRM) mode.A guard column was used and the flow rate was 0.4 mL·min-1. Result: It showed the highest biliary excretion at 0.5-1 h after administration.The biliary excretion rate of oxyresveratrol was 0.737% within 12 hours. Conclusion: This analytical method is rapid (3 min for each sample)

selective

precise

accurate

and reliable for in vivo analysis of oxyresveratrol.