HPLC determination of paeonol and paeoniflorin in Xiaoyin pills

Objective:To establish an RP-HPLC for determination of the content of paeonol and paeoniflorin in Xiaoyin pills.Methods:Both paeonol and paeoniflorin were separated on an RP C_(18) column.The determination of paeonol with acetonitrile-0.1%triethylamine (adjusted to pH 6 with phosphoric acid) (55:45) as the mobile phase.The flow rate was 1 mL·min~(-1) and the detection wavelength was 274 nm;The determination of paeoniflorin with acetonitrile-water(25:75,pH=7) as the mobile phase.The flow rate was 1 mL·min~(-1) and the detection wavelength was 229 nm.Results:The linear ranges were 0.125-5 μg·mL~(-1) for paeonol and 5-80 μg·mL~(-1) for paeoniflorin.The mean recovery of high,middle,low concentration was 100.6%,102.6%,97.33%with corre- sponding RSD of 0.52%,0.45%,0.73%for paeonol and 100.1%,100.2%,98.57%with corresponding RSD of 0.89%,1.2%,1.2%for paeoniflorin.Conclusion:The method is simple,sensitive and reproducible.