Abstract: Objective To establish an ultra performance liquid chromatography (UPLC) method for the determination of psoralen and isopsoralen in compound Ziling capsules. Methods The separation was performed on ACQUITY UPLC BEH C18(2.1 mm× 100 mm, 1.7 m) with 0.05% formic acid：methamol (50∶ 50) mixture as mobile phase at a flow rate of 0.2 mL·min-1, and UV detection at 246 nm. Results The calibration curves for psoralen and isopsoralen were linear in the range of 10~200 mg·L-1 (rPsoralen=0.999 6, rIsopsoralen=1.000 0). The average recoveries of psoralen and isopsoralen were (100.69± 1.38)% and (100.67± 1.29)%, respectively. Conclusion The method was simple, accurate and reliable for the quality control of compound Ziling capsules.

Key words: compound Ziling capsules, psoralen, isopsoralen, UPLC