Objective: A rapid and sensitive ultra performance liquid chromatography tandem mass spectrometry method (UPLC-MS/MS) was developed and validated for simultaneously determination of phenolic acids and flavonoids in rat plasma after oral administration of Shuanghuanglian preparation. Method: Plasma samples were pretreated by n-butanol-ethyl acetate(1:1).The separation was preformed on an Waters Acquity HSS T3 C18 column(2.1 mm×100 mm

1.7 μm) and the flow rate was set at 0.4 mL·min-1 with mobile phase of acetonitrile-methanol(4:1)-0.4% formic acid for gradient elution.The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring(MRM) via electrospray ionization(ESI) source with positive mode. Result: All calibration curves had good linearity(R2>0.992).RSDs of precision and accuracy were all satisfied.After oral administration of Shuanghuanglian preparation

a remarkable increase in values of AUC0-t and AUC0-∞ of neochlorogenic acid

chlorogenic acid

cryptochlorogenic acid

baicalin

oroxylin A-7-O-β-D-glucuronide

wogonoside and baicalein was observed by compared with Lonicerae Japonicae Flos extract group or Scutellariae Radix extract group;but the elimination rate of phenolic acids and flavonoids in Shuanghuanglian preparation was slower than the single herb extract. Conclusion: The developed method is successfully applied to pharmacokinetic study of nine active ingredients in Shuanghuanglian preparation

this study can provide experimental evidence for elucidating rationality of compatibility of this preparation.