Objective: To establish a reversed-phase HPLC method for the determination of psoralen and isopsoralen in Qubaibairesi tincture. Method: The method of RP-HPLC was carried out with Scienhome kromasil ODS-1 column (4.6 mm×250 mm

5 μm); the flow rate of the mobile phase of methanol-water (55∶45) was 1.0 mL·min-1; the column temperature was maintained at 40 ℃ and the detection wavelength was set at 246 nm. Result: The linear ranges of psoralen and isopsoralen were 6.12-18.36 mg·L-1(r=0.999 0) and 6-18 mg·L-1(r=0.999 1) respectively. The recoveries were 101.57% (psoralen) and 100.39%(isopsoralen)

and their RSDs were 1.6%(psoralen) and 1.5%(isopsoralen). Conclusion: The method is simple

accurate and can be used to control quality of Qubaibairesi tincture.