Determination of avermectin, diclazuril, toltrazuril and metabolite residues in pork by high performance liquid chromatography-tandem mass spectrometry

A method for the determination of avermectin ivermectin doramectin moxidectin eprinomectin diclazuril toltrazuril and its two metabolite residues in pork was developed using QuEChERS method with high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The sample was extracted with acetonitrile and purified through QuEChERS method using ODS as the sorbent. The target compounds were separated on a Venusil ASB C18 column (150 mm x 2. 1 mm , 3. 0 mu m) and detected by HPLC-MS/MS. The linear ranges were 0. 005 -0. 2 mg/L and the correlation coefficients were all above 0. 990. The average recoveries and the relative standard deviations ranged from 73. 2% to 91. 5% and from 12% to 17% at the spiked levels of 0. 005 , 0. 01 and 0. 02 mg/kg for the 9 analytes in pork matrix. This method is reliable, and suitable for the determination of the residues of avermectin and related compounds in pork.