A LC/MS/MS method was used to determine polydatin and its metabolite in Sprague-Dawley (SD) rat plasma. The polydatin and resveratol in plasma were extracted twice by vortexing with 2. 0 mL acetoacetate. The organic phase was removed into the tubes and then evaporated in the Zymark TurboVap LV Evaporator. The residue was dissolved in 50 mu L methanol. 10 mu L solution was drawn and detected by LC/MS/MS. Lichrospher C-18 was used (150 mm x 2. 1 mm, 5 mu m) with the mobile phase gradient elution of acetonitrile-waters. Electrospray ionization-mass spectrometry (ESI-) source was used as detector and was operated in negative ion mode selected multiple reactions monitoring (MRM) mode with the transitions of m/z 389/227 (polydatin) and m/z 227/143 (resveratrol) used as quantifying, respectively. Under the optimized LC/MS/ MS conditions, polydatin, resveratol and internal standard can be well separated, and their ionization efficiency was satisfactory. The standard curve of polydatin and resveratrol were linear in the concentration range of 0. 4 - 200 mu g/L. The recoverier of analytical method for polydatin were 106. 2% 97. 8% and 91. 6%, for resveratrol were 113. 2% 103. 6% and 93. 4% when the plasma drug concentration was 1, 20 and 100 mu g/L respectively. Intra-day and inter-day precises expressed by relative standard derivation(RSD) were less than 15%. The assay method was sensitive, accurate, fast and suitable to determine the polydatin and its metabolite in SD rat plasma.
