玉米粉中吡虫啉、三唑酮、乙草胺与异丙甲草胺的QuEChERS/高效液相色谱-串联质谱快速检测

摘要

A QuEChERS/HPLC-MS/MS method was developed for the simultaneous determination of imidacloprid,triadimefon,acetochlor and metolachlor residue in corn flour.The residues were extracted from samples with acetonitrile and cleaned up by dispersive method using PSA and GCB,then detected by high liquid chromatography-mass spectrometry (HPLC-MS/MS) under multiple reaction monitoring mode,and quantified by the matrix-matched standard solution.The results showed the method had a good linearity(r2 ≥0.998) in the range of 0.005-1.000 mg/L.Average recoveries at three spiked levels of 0.05-1.00 mg/kg were in the range of 74.9％-98.4％ with relative standard deviations (n =5) of 1.6％-5.3％.The limits of detection(LOD) for 4 pesticides were in the range of 0.001-0.26 μg/kg,and limits of quantitation(LOQ) were in the range of 0.004-0.867 μg/kg.With the advantages of rapidness,simplicity,high sensitivity and good reproducibility,the method is suitable for the determination of target pesticides in corn flour.%建立了玉米粉中吡虫啉、三唑酮、乙草胺和异丙甲草胺4种常用农药的QuEChERS/高效液相色谱-串联质谱残留分析方法.前处理采用QuEChERS方法,以乙腈为提取剂,N-丙基乙二胺(PSA)和石墨化碳黑(GCB)为分散净化剂,并利用高效液相色谱-串联质谱在多反应离子监测模式(MRM)下进行检测,基底匹配工作曲线法定量.结果表明:4种农药在0.005 ～1.000 mg/L浓度范围内均具有良好的线性关系(r2≥0.998);在0.05 ～1.00 mg/kg加标水平下的平均回收率为74.9％ ～ 98.4％,相对标准偏差(n=5)为1.6％～5.3％;方法检出限(LOD)为0.001 ～0.26 μg/kg;定量下限(LOQ)为0.004 ～0.867 μg/kg.该方法分析速度快、灵敏度高、重现性好,适用于玉米粉中吡虫啉、三唑酮、乙草胺和异丙甲草胺4种农药残留的快速检测和确证.