气相色谱-电子捕获检测器快速测定水产品中多种农药及兽药残留

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

称取2.000g样品,加入含0.2%(φ)甲酸的乙腈(85+15)溶液10mL,涡旋混合30s,振荡提取30min,以10 000r·min-1转速离心5min,取上清液。用2mL的含0.2%(φ)甲酸的乙腈(85+15)溶液活化Oasis PRiME HLB小柱后,将上述上清液全部通过Oasis PRiME HLB小柱并收集滤液,于50℃水浴下氮吹至干,加入100μL衍生化试剂[N,O-双(三甲基硅烷基)三氟乙酰胺-三甲基氯硅烷(质量比为99∶1)],涡旋10s,于65℃恒温反应30min后,于50℃水浴下氮吹至干,用正己烷定容至1.0mL,以DB-5/DB-35色谱柱(30m×0.25mm,0.25μm)分离11种拟除虫菊酯类农药和3种氯霉素类兽药,采用电子捕获检测器。11种农药的线性范围为0.10~0.80mg·L-1,3种兽药的线性范围为5.0~40mg·L-1,检出限(3S/N)在0.000 1~0.008 0μg·g-1之间。加标回收率为85.6%~119%,测定值的相对标准偏差(n=6)不大于9.0%。

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 100μL of derivatization reagent[N,O-bis（trimethylsilyl）trifluoroacetamide-trimethylchlorosilane（mass ration of 99∶1）]was added to the resdiue,and the mixture was vortexed for 10 sand let react at a constant temperature of 65℃for30 min.After the mixture was dried by N2-blowing in a water bath at 50 ℃,and the residue was made up to1.0 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,0.25μm）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（3 S/N）were between 0.000 1-0.008 0μg·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%.