Abstract: To establish a UPLC-MS method for simultaneous determination of gallic acid,oxypaeoniflorin,albiflorin,paeoniflorin and benzoylpaeoniflorin in Radix Paeoniae Rubra. An Acquity UPLC BEH C18 column (2.1 mm×50 mm,1.7 μm) was used for the chromatographic separation with the mobile phase consisting of 0.1% formic acid in acetonitrile (A) and 0.1% formic acid in water (B) by gradient elution.Selected ion recording (SIR) mode was used for detection.The linear ranges of gallic acid,oxypaeoniflorin,albiflorin,paeoniflorin and benzoylpaeoniflorin were determined to be 0.134~31.250,0.014~2.784,0.471~30.750,0.293~75.040 and 0.158~40.360 μg/mL,respectively.The average recoveries were 91.36%~112.83%,with RSDs of 1.1%~8.9%.The developed UPLC-MS method was accurate and effective.It can be used for the quality evaluation of Radix Paeoniae Rubra with simultaneous determination of 5 marker compounds.

Key words: Radix Paeoniae Rubra, UPLC-MS, main index compounds, selected ion recording