Abstract:To determine the residues of chlorantraniliprole，spirodiclofen，bitertanol and thiabendazole in food products of animal origin，a method was established by using ultra-high performance liquid chromatographytandem mass spectrometry.With acetonitrile as the extraction solvent，a modified QuEChERS method was chosen to purified the analytes from the food sample.The target compounds were separated by a C18 UPLC column，then detected by electro-spray ionization（ESI+）and multiple reaction monitoring（MRM）mode.Quantification was performed by peak area external standard methods using matrix-matched calibration curves，which were linear in the range of 0.005 mg/L-0.200 mg/L with good linear relationships.The correlation coefficients were better than 0.999.The limit of quantification （LOQ）of chlorantraniliprole，spirodiclofen，bitertanol and thiabendazole was 0.30，3.00，0.50，0.10 μg/kg respectively.At 0.005，0.050 ，0.200 mg/kg spiked levels for milk，pork，liver and egg samples，the recoveries were between 82%and 109%，and the relative standard deviations（RSD）were in range of 2.1%to 8.5%（n=5）.This method was simple，quick，accurate，and could be applied to the determination of the four pesticides residues in food products of animal origin.