Simultaneous determination of baicalin,baicalein and wogonin in Qinlian tablets by HPLC

Objective To establish RP-HPLC method for simultaneous determination of baicalin,baicalein and wogonin in Xiaoyan tablets(traditional Chinese medicines).Methods A column packed with Agilent Eclipse XDB-C18(250 mm×4.6 mm,5 μm)was used;the mobile phase was methanol-0.4%H3PO4 by gradient elution and the detection wavelength was set at 277 nm;the flow rate was 1.0 mL · min-1,the injection volume was 5 μL,the column temperature was 30 ℃.Results The linear range of baicalin was from 13.82 to 125.6 mg · L-1,r=0.999 8(n=6);the linear range of baicalein was from 10.76 to 86.08 mg · L-1,r=0.999 9(n=6);the linear range of wogonin was from 8.35 to 66.80 mg · L-1,r=0.999 9(n=6).The average recovery of baicalin was 100.50%,RSD=0.8%;the average recovery of baicalein was 99.76%,RSD=1.5%;the average recovery of wogonin was 98.83%,RSD=1.2%.Conclusions The method is found to be convenient,quick and accurate,and be used for the quality control of Xiaoyan tablets.