分散固相萃取-液相色谱-串联质谱法测定典型小宗作物中6种农药残留

Determination of Six Pesticide Residues in Classic Minor Crops by Liquid Chromatography-Tandem Mass Spectrometry with Dispersive Solid Phase Extraction

建立生姜、红薯、土豆、荔枝中多菌灵、吡虫啉、涕灭威、三唑酮、乙草胺、苯醚甲环唑的液相色谱-串联质谱检测方法。样品经乙腈溶液提取,50 mg N-丙基乙二胺吸附剂、25 mg十八烷基键合硅胶(C_(18))净化,C_(18)色谱柱分离,0.1%甲酸溶液-甲醇作为流动相进行梯度洗脱,在电喷雾正离子电离模式下,质谱多离子监测模式定量分析,基质标准曲线外标法定量。结果表明,6种农药在10~500μg/L范围内呈良好的线性关系,相关系数(r)均大于0.995。3个加标水平下,6种农药的平均回收率为87.9%~110.3%,相对标准偏差不大于14.6%。该方法简单、快速、灵敏度高,能够满足小宗作物农药残留的监控要求。

A simple analytical method was established using dispersive solid phase extraction combined with liquid chromatography-positive mode electrospray ionization-tandem mass spectrometric(LC-MS/MS)for the determination of six pesticide residues in ginger,sweet potato,potato,and litchi,including carbendazim,imidacloprid,aldicarb,triadimefon,acetochlor and difenoconazole.The analytes were extracted with acetonitrile and cleaned up using primary secondary amine(PSA)and octadecyl silane(C18).Qualitative analysis of six analytes was carried out under the positive scanning model after the chromatographic separation on a reversed phase C18column with gradient elution using a mobile phase composed of methanol and0.1%formic acid aqueous solution.A good linearity was observed for the six pesticides in the range of10-500μg/L with a coefficient of determination(r)of greater than0.995.The recoveries of the pesticides in four classical minor crops were in the range of87.9%-110.3%at three spiked concentration levels,and the precision,as indicated by relative standard deviations(RSDs,n=5),was not more than14.6%.The method is simple,rapid and sensitive,and can meet the requirements for the determination of pesticide residues in minor crops.