【摘要】 建立了基于QuEChERS方法的液相色谱-串联质谱同时测定甜玉米及毛豆中32种磺酰脲类除草剂残留的方法。以提取液净化前后蒸发残渣质量及回收率为考察指标,评估了C18、氧化锆包覆硅胶(Z-Sep)/C18混合物、C18键合锆胶(Z-Sep+)3种分散吸附剂对甜玉米的净化效果,结果 Z-Sep/C18吸附剂的净化效果最佳。样品采用乙腈提取、无水硫酸镁及氯化钠盐析、Z-Sep/C18分散固相萃取净化;液相色谱以CSH C18色谱柱梯度洗脱分离,质谱分析采用电喷雾负离子电离、按时间表的多反应监测模式(Scheduled MRM),以基质匹配校准曲线外标法进行定量。32种农药在甜玉米及毛豆中3个添加水平(10、20、100μg/kg)的回收率为80.0%~108.2%,相对标准偏差为1.2%~13.0%,32种农药的定量限(S/N≥10)为0.2~5.0μg/kg。方法简便、灵敏、环保,适用于甜玉米及毛豆中32种磺酰类除草剂残留的定性定量分析。更多还原

【Abstract】 A fastmethod based on QuEChERSmethodology for the simultaneous determination of 32 sulfonylurea herbicide residues in sweet corns and green soybeans was developed using liquid chromatography-tandemmass spectrometry(LC-MS/MS).The clean-up effects of three dispersive sorbents were evaluated in terms of the residuemass for extracts after evaporation and recoveries.The three sorbents were C18,amixture of two sorbents—silica coated with zirconium dioxide(Z-Sep)and C18,a bonded C18 zirconia-coated silica(Z-Sep+).As a result,the best effects were obtained from using Z-Sep/C18 sorbents.The samples were extracted with acetonitrile,and salted out with anhydrousmagnesium sulphate and sodium chloride.The extracts were cleaned up with dispersive solid phase extraction using Z-Sep/C18 sorbents.Chromatographic analysis was carried out using a CSH C18 column with gradient elution.The pesticides were analyzed by negative electrospray ionization tandemmass spectrometry under scheduledmultiple reactionmonitoringmode.The quantification was achieved usingmatrixmatched standard calibrations as the external standard.The recoveries at fortification levels of10,20,100 μg/kg in sweet corns and green beans ranged from 80.0% to 108.2% with the relative standard deviations of 1.2%-13.0%.The limits of quantification(S/N≥10)were 0.2-5.0μg/kg.Themethod has been proven to be simple,sensitive,environmental,and thus suitablefor the determination of the 32 sulfonylurea herbicide residues in sweet corns and green soybeans.更多还原