气相色谱-串联质谱多反应监测及同步子离子全扫描定性定量分析蔬菜中287种农药残留

Determination of 287 pesticide residues in vegetable by gas chromatography-tandem mass sepctometry with multiple reaction monitoring and production scan

建立了气相色谱-三重四极杆串联质谱(GC-MS/MS)多反应监测(T-SRM)及同步二级全谱同时定性定量检测蔬菜中287种农药残留的方法。基于改进的QuEChERS方式进行样品前处理,使叶绿素在乙腈-水体系中的溶解度降低而析出,经0.2μm有机相滤膜过滤,有效的去除了叶绿素,净化后采用气相色谱-三重四极杆串联质谱在多反应监测(T-SRM)模式下进行外标法定量测定。结果表明287种分析物的浓度在5.0～100μg/L范围内线性关系良好,相关系数均大于0.995,定量限为10μg/kg。进行3个水平(10,20和50μg/kg)的加标回收试验,其回收率为45%～110%,其中277个目标物回收率为60%～110%。方法的相对标准偏差(RDS)小于20%。引入了一种新的MRM监测模式(T-SRM),并且在定量限10μg/kg残留浓度下可同步获得二级全扫描质谱图。该方法已广泛应用于蔬菜中多种农药残留的快速检测与确证的日常检测工作中。

A simple method for the determination of 287 pesticide residues in vegetable by gas chromatography- triple quadrupole tandem mass spectrometry（GC-MS/MS） was established. The vegetable sample was pretreated in a single extraction, based on a modified ＂QuEChERS method＂, and further purified on the chlorophyll innovation, by changing the polarity of the system, so that the solubility of chlorophyll in acetonitrilewater system was reduced and precipitated, and then filtered by 0. 2 I^m organic membrane phase, leading to effective removal of chlorophyll. Limits of detection obtained were lower than 10 lxg/kg and pesticide recoveries spiked with 10, 20 and 100 Ixg/kg yielded average recoveries in the range between 60% and 110% for 277 analytes. The proposed method featured good precision, expressed as relative standard deviation was less than 20%. Besides the evaluation of the sample preparation approaches, we also discuss the use of advanced software features associated to MRM method development that overcome several limitations and drawbacks associated to MS/MS methods （ time scheduled and acquisition limitations）. The identification and confirmation of the compounds were based on retention time matching along with the presence （and ratio） of two typical MRM transitions. Product ion scan could be obtained synchronized under the limit of quantification less than 10 trg/kg residual concentration. The proposed method was applied successfully to the residue determination of the selected pesticides in commercial vegetable samples.