A simple, sensitive and specific high performance liquid chromatography-tandem mass spectrometry （HPLC-MS/MS）method combined with solid phase extraction has been developed and validated for the simultaneous quantification of paeoniflorinand albiflorin in rats plasma and tissue homogenate after administration of total glycosides of paeony （TGP）. Chromatographicseparation was achieved on a C15 column （150 mmx4.6 mm, 5 pro） with mobile phase consisted of acetonitrile-0.05% formicacid aqueous （20： 80, v/v） at a flow rate of 0.5 mL/min. The analytes were detected with triple-quadrupole mass spectrometer usingturbo ion spray with negative ionization in the multiple reaction-monitoring （MRM） modes. The results of method validationconformed to the requirements for the determination of biological samples. This method was successfully applied to thepharmacokinetics and tissue distribution study of TGP in rats. The results showed that paeonifiorin and albiflorin wereabsorbed and reached peak value quickly, and had the similar pharmacokinetic characteristics. Both of them underwent a rapid andwide distribution in the tissues throughout the whole body, among which stomach was the main distribution tissue. Moreover, theyhad the ability to cross the blood-brain barrier.
