Abstract: Objective To conduct a comprehensive inspection and risk assessment of exogenous harmful residues in Isatidis Radix so as to provide reference for safe use of Isatidis Radix. Methods Thirty-three forbidden pesticides were determined using gas chromatography-tandem mass spectrometry (GC-MS-MS) and high performance liquid chromatography-tandem mass spectrometry (HPLC-MS-MS) methods. Four aflatoxins were determined with the high performance liquid chromatography with fluorescence detection after immunoaffinity column clean-up (IC-HPLC-FD) method. Five heavy metals and harmful elements were determined via inductively coupled plasma mass spectrometry (ICP-MS). Sulfur dioxide was determined by means of ion-chromatography (IC). Subsequently, risk assessment was performed using the target hazard quotient (THQ) method. Results Thirty-three forbidden pesticides or aflatoxin B1, B2, G1 and G2 were not detected in 64 batches of Isatidis Radix. Contents of sulfur dioxide were all below the limit specified by the Chinese Pharmacopeia (150 mg·kg-1). THQ of sulfur dioxide, Pb, Cd, As, Hg and Cu in 64 samples and Isatidis Radix were far below one. Based on risk assessment, limits of Pb, Cd, As, Hg and Cu in Isatidis Radix were proposed as 2, 1, 2, 0.2 and 20 mg·kg-1, respectively. Conclusion The risk of exogenous harmful residues in Isatidis Radix is low.

Key words: Isatidis Radix, harmful residues, pesticides, heavy metals, aflatoxins, sulfur dioxide, risk assessment