在线凝胶色谱-串联三重四极杆质谱法测定大豆油中42种农药残留

建立了在线凝胶色谱-串联三重四极杆质谱（GPC-GC-MS/MS）法测定大豆油中的42种农药残留。采用在线凝胶色谱进行在线净化，除去大豆油中大部分油脂，有效缩短样品前处理时间；结合多反应监测（MRM）采集方式，可减少基质干扰，提高方法的选择性。结果表明：在1~50 μg/L浓度范围内，大部分农药的线性相关系数均在0.999以上；方法检出限为0.02~2.59 μg/kg，方法定量限为0.08~8.62 μg/kg；在10、50、300 μg/kg加标浓度下，农药的加标回收率在70.4%~119%之间。以α-666等11种农药为例，比较了GPC-GC-MS/MS法、GPC-GC/MS法、GC-MS/MS法的实验结果，发现采用GPC-GC-MS/MS法的MRM数据采集模式测定大豆油中农药残留具有良好的抗基质干扰能力，可获得最低的方法检出限及最高的回收率。该方法操作简单、灵敏度高、稳定性好，可用于大豆油中农药残留的测定，也适用于复杂基质中痕量农药残留的定性和定量分析。

Determination of 42 Pesticide Residues in Soybean Oil Using On-Line GPC-GC-MS/MS

In view of the great harm to the human body of pesticides, the national food safety standards and the International Food Code Committee standards limit the maximum residue limits of pesticides in soybean oil. Gas chromatography-mass spectrometry (GC/MS) is often used for the identification and quantitative detection of the compound, because of the characteristics of high separation efficiency. However, the current GC/MS is mainly used in the combination of single quadrupole GC/MS and selective ion monitoring (SIM) technique. The selectivity of SIM acquisition mode is poor, and it is easily disturbed by the matrix. The multiple reaction monitoring (MRM) technique of the triple quadrupole gas chromatography-mass spectrometry （GC-MS/MS） can effectively eliminate the interference of the matrix, which is beneficial to the determination of pesticide residues in complex matrix. A reliable pesticide residues analysis method in soybean oil was developed in this paper, based on on-line gel permeation chromatography coupled with triple quadrupole gas chromatography-mass spectrometry （GPC-GC-MS/MS）. GPC system served as on-line purifying pretreatment to remove most part of remained fat in soybean oil and effectively reduced the time of sample pretreatment. At the same time, multiple reaction monitoring (MRM) acquisition mode of GC-MS/MS could greatly reduce the matrix interference and provide much better selectivity. The results show that the relative coefficients are above 0.999 with the most of pesticides standard solutions from 1 to 50 μg/L. The method detection limits range from 0.02 μg/kg to 2.59 μg/kg, and the quantitative limits range from 0.08 μg/kg to 8.62 μg/kg. The recoveries are 70.4%-119% with added concentration as 10, 50, 300 μg/kg. By comparing the experimental results of GPC-GC-MS/MS, GPC-GC-MS and GC-MS/MS, the MRM data acquisition mode of GPC-GC-MS/MS can get the lowest detection limit and the best recovery of pesticide residues in soybean oil. The detection method based on on-line GPC and GC-MS/MS can simplify the process of sample pretreatment, reduce the matrix interference, improve the selectivity and sensitivity of the analysis, and which can be applied to the qualitative and quantitative analysis of trace residues in complex matrix.