食品中42种农药残留的气相色谱—质谱选择离子测定法

Determination of 42 Kinds of Pesticide Residues with Gas Chromatography Mass Spectrometry and Selected Ion Monitoring

目的建立一种测定食品中有机磷、拟除虫菊酯、有机氯、氨基甲酸酯类和除草剂农药残留的气相色谱质谱方法。方法该法采用丙酮、二氯甲烷提取，40℃水浴旋转蒸发近干，以Envi—Carb柱和Sep—Pak—NH2柱净化，以气相色谱-质谱选择离子监测方式分析检测有机磷、有机氯、拟除虫菊酯、氨基甲酸酯和除草剂等42种农药残留。结果所有42种农药均在36min内流出，分离良好，农药标准的线性范围在0．005～1．0μg/ml，相关系数r均在0．99以上，低、高2种浓度加标回收率均在90％～96％之间，相对标准偏差均小于10％，方法最低检出限在0．005mg／kg（S／N=3）。结论方法选择性强，适合于食品中有机磷、有机氯、拟除虫菊酯、氨基甲酸酯和除草剂农药残留的测定，且准确度好，精密度高，可快速一次检测42种农药，达到残留量检测中所要求的检测浓度水平。

[ Objective] To establish the method of gas chromatography mass spectrometry （GC-MS） and selected ion monitoring （ SIM ） for the determination of organophosphorus, pyrethroid, organochlorine, carbamate and weedicide pesticide residues in foods. [ Methods] The pesticides were extracted with acetone and dichloromethane, warmed with water at 40℃, and cireumrotated and evaporated until it was nearly dry, then it was purified by Envi Carb column and Sep Pak NH2 column. Afterwards, gas chromatography mass spectrometry （GC-MS） and selected ion monitoring （SIM） were used to determine 42 pesticide residues, such as organophosphorus, pyrethroid, organoehlorine, carbamate and weedicide. [ Results] All the 42 kinds of pesticide residues were drained out within 36 minutes, the separation was fine; the standard linear range was between 0. 005 - 1.0μg/ml; correlation coefficient r was above 0.99 ; the labeled recovery rates were between 90% and 96% ; the relative standard deviations （ RSD ） was below 10% ; the limit of determination （ LOD ） was 0. 005mg/kg （ S/N = 3 ）. [ Conclusion] This method is suitable for determining pesticide residues in foods with satisfactory sensitivity, accuracy and precision; it can rapidly detect 42 kinds of pesticide and the concentration level reaches the requirement for detection.