固相萃取/气相色谱-串联质谱法测定土壤中多种农药残留

Determination of pesticide residues in soil by gas chromatography-tandem mass spectrometry coupled with solid phase extraction

建立了固相萃取/气相色谱-串联质谱法(GC-MS/MS)同时测定土壤中多种农药残留的分析方法。样品采用乙腈提取,提取液经石墨化碳/氨基固相萃取小柱净化后,采用气相色谱-串联质谱检测。本研究对土壤样品前处理方法进行了优化,考察了采用不同净化方法、不同前处理条件对分析结果的影响。在优化条件下,125种农药的响应在0. 01~0. 8 mg/L质量浓度范围内线性良好,相关系数R^2> 0. 9908。在0. 08,0. 2,0. 4 mg/kg的添加水平分别进行土壤农药回收率的测定,除氧乐果等3种农药外平均回收率在71. 3%~121. 6%之间,相对标准偏差在0. 15%~13%之间。此方法可满足土壤中多组分农药残留同时分析的要求。

A method was developed for simultaneous determination of various pesticides in soil by solid-phase extraction/gas chromatography tandem-mass spectrometry( GC-MS/MS). The samples were extracted with acetonitrile,and then the extract was cleaned up by carbon/NH2 solid-phase extraction cartridges and the analytes were determined by GC-MS/MS. In the experiment,the pretreatment methods of soil samples were optimized,the effects of different purification methods and different pretreatment conditions on the results were investigated. Under the optimized conditions,the method had good linear relationships in the range of 0. 01-0. 8 mg/L for 125 pesticides,and the correlation coefficients were more than 0. 9908. When the spiked levels were 0. 08,0. 2 and 0. 4 mg/kg,the average recoveries of the 125 pesticides were between 71. 3%-121. 6%,with relative standard deviations( RSDs) between 0. 15%-13%,except for 3 kinds of pesticides,such as omethoate. This method could meet the requirements for analysis of pesticides in soil with high accuracy.