Rapid Determination of Pesticide and Veterinary Drug Residues in Aquatic Products by Gas Chromatography-Electro Capture Detector

10 mL of acetonitrile (85+15) solution containing 0.2% (φ) formic acid was added to 2.000 g of the sample. The mixture was vortexed for 30 s, extracted by oscillation for 30 min, and centrifuged at 10 000 r·min^-1 for 5 min, and the supernatant was taken. After the Oasis PRiME HLB cartridge was activated with 2 mL of acetonitrile (85+15) solution containing 0.2% (φ) formic acid, the supernatant was passed through the Oasis PRiME HLB cartridge and the filtrate was collected and dried by N₂-blowing in a water bath at 50℃. Then 100 μL of derivatization reagentN,O-bis(trimethylsilyl) trifluoroacetamide-trimethylchlorosilane (mass ration of 99:1) was added to the resdiue, and the mixture was vortexed for 10 s and let react at a constant temperature of 65℃ for 30 min. After the mixture was dried by N₂-blowing in a water bath at 50℃, and the residue was made up to 1.0 mL with n-hexane. 11 pyrethroid pesticides and 3 chloramphenicol veterinary drugs were separated on a DB-5/DB-35 column (30 m×0.25 mm, 0.25 μm) and determined by using an electron capture detector. The linear range of 11 pesticides was 0.10-0.80 mg·L^-1, the linear range of 3 veterinary drugs was 5.0-40 mg·L^-1, and the detection limits (3S/N) were between 0.000 1-0.008 0 μg·g^-1. Values of recovery obtained by standard addition method ranged from 85.6% to 119%, and RSDs (n=6) were not more than 9.0%.