Abstract: AIM:To establish a sensitive and rapid liquid chromatographic-tandem mass spectrometry(LC-MS/MS) method for the quantitative analysis of dehydrated puerarin in rat plasma,and its application for pharmacokinetic studies.METHODS:A plasma sample was pretreated by one-step protein precipitation by the addition of five volumes of methanol.The chromatographic separation was achieved on a Zorbax SB-C18 column(4.6 mm×150 mm I.D.5.0 μm,Agilent,USA) at 40℃ at a flow rate of 0.6 mL·min-1 by an isocratic elution consisting of 10 mmol·L-1 ammonium acetate in methanol and water containing 0.1% formic acid in a ratio of 20:80(V/V).Detection was performed on a triple quadrupole mass spectrometer in multiple-reaction monitoring(MRM) mode.An atmospheric pressure chemical ionization(APCI) interface in positive ionization mode was used by monitoring the transitions from m/z 399.1 →281.0(dehydrated puerarin) and m/z 271.0→215.0(internal standard,IS).RESULTS:Calibration curves were linear in the concentration range from 1.50 to 5400 ng·mL-1,and the lower limit of quantification(LLOQ) was 1.50 ng·mL-1 in rat plasma.The accuracy and precision values,which were calculated from three different sets of quality control samples analyzed in sextuplicate on three different days,ranged from 95.73% to 103.18%,and from 4.33% to 7.86%,respectively.CONCLUSION:The method was successfully applied to assess the pharmacokinetics of dehydrated puerarin after oral administration in rats.