Abstract: Objective： To establish an high performance liquid chromatography-mass spectrometry method for the determination of aristolochic acid Ⅰ in xinfang biyan capsules， and provide theoretical basis for its safety control. Methods：Waters ACQUITY UPLC HSS T3 (2.1 mm×100 mm， 1.8 μm) column was used. Methanol-0.1% formic acid (containing 1 mmol·L-1 ammonium acetate) solution was used as mobile phase， gradient elution， flow rate of 0.3 mL·min-1， positive ion mode of electric spray ion source， multi reaction monitoring， external standard determination. Results： The linear relationship of aristolochic acid I was good within the range of 0.320 9-32.092 5 μg·mL-1 (r2=0.999 5)， with an average recovery rate of 95.04%. Aristolochic acid I was detected in all 104 batches of samples， with a content of 7.91-90.75 ng·g-1. Conclusion： This method is sensitive， accurate， reliable， and highly specific， and can be used for the limited detection of aristolochic acid I in xinfang biyan capsules.

Key words: font-size:medium, "> , Xinfang biyan capsules； Aristolochic acid Ⅰ； Safety； High performance liquid chromatography-mass spectrometry； Limit test