液相色谱串联质谱法检测油菜籽中27种除草剂残留

基于液相色谱-串联质谱仪(LC-MS/MS),建立了油菜籽中27种除草剂残留的分析方法。样本采用改进的QuEChERS方法提取净化,用乙腈-乙酸溶液提取30 min,添加缓冲盐,振荡,冷冻离心去除脂肪和蛋白,将上清液转移至净化管中,加入PSA(N-丙基乙二胺)/C18(BONDESIL-C18)/GCB(石墨炭黑)混合粉末净化包,去除基质干扰,过0.22μm有机相滤膜。利用LC-MS/MS外标法定量分析。方法学考察结果表明,检出限为0.14~0.92μg/L,油菜籽基质中27种除草剂在2.0~200μg/L浓度范围内线性关系良好,相关系数r≥0.992;在5、10、25μg/kg添加水平下,27种除草剂的平均加标回收率为75.3%~102.0%,相对标准偏差在1.3%~10.4%之间。将该方法用于实际油菜籽样品的检测,结果显示所有样品均符合农药残留限量标准。该方法具有简便、灵敏度高、精密度和准确度好的优势,适合油菜籽中27种除草剂残留检测。

Simultaneous Determination of 27 Herbicides Residues in Rapeseed by LC-MS/MS

A liquid chromatography-tandem mass spectrometric method(LC-MS/MS)was developed for the simultaneous determination of 27 herbicides residues in rapeseed.Samples were extracted and purified by improved QuEChERS method.The samples were extracted with acetonitrile-acetic acid solution for 30 min,buffer salt was added and oscillation,the fat and protein were removed by freezing centrifugation.The supernatant was transferred to the purification tube.PSA/C18/GCB was added to remove matrix interence,0.22μm organic phase filtration membrane was used for filtration,and then quantitatively analyzed by LC-MS/MS external standard method.The results of methodological investigation indicated that the limits of detection were 0.14~0.92μg/L.All of herbicides showed good linear with r≥0.992 from 2.0 to 200μg/L and the average recoveries of the 27 herbicides at 5,10,25μg/kg were 75.3%~102.0%with the relative standard deviations(RSDs)ranging from 1.3%~10.4%.This method was used to detect these herbicide residues in rapeseeds.The detection results indicated the contents of 27 herbicides in all of rapeseeds were below the maximum residue limits.This method showed simple,highly sensitive and accurate,which could be used to detect 27 herbicides residues in rapeseed.