QuEChERS-气相色谱-质谱联用法快速测定人参中农药多残留

建立了QuEChERS-气相色谱-质谱联用（GC-MS）法同时测定人参中20种农药残留量的检测技术。样品前处理采用改进的QuEChERS方法，人参粉加水浸润后，用乙腈均质提取，用N-丙基乙二胺（PSA）和MgSO₄净化，结合GC-MS检测系统，在电子轰击源（EI）选择离子监测（SIM）模式下进行检测，使用HP-5毛细管柱进行分离。在优化条件下，20种农药在一定范围内线性关系良好，相关系数大于0.990，方法检出限（信噪比S/N=3）为0.001~0.007 mg/kg，定量限（S/N=10）为0.002~0.024 mg/kg，平均回收率为70.41%~114.06%，相对标准偏差（RSD）为0.76%~15.47%。该方法操作简单快捷、灵敏度高。

Rapid determination of pesticide multiresidues in panax ginseng by QuEChERS-gas chromatography-mass spectrometry

In this study, the extraction and purification improvements of the QuEChERS method were coupled with gas chromatography-mass spectrometry (GC-MS) to determine 20 pesticides in panax ginseng. Dry ginseng powder was mixed with water, and the solution was then extracted with acetonitrile and purified with N-propylethylenediamine (PSA) and MgSO₄ to remove co-extractives that might interfere with the results. The target compounds were detected after electron-impact ionization in selected ion monitoring (SIM) mode. Under optimum conditions, the method gave a good linear relationship for the determination of the pesticides within a certain concentration range, with correlation coefficients greater than 0.990. Moreover, the limits of detection (S/N=3) were 0.002-0.007 mg/kg, the limits of quantification (S/N=10) were 0.002-0.024 mg/kg, and the average recoveries for pesticides in panax ginseng were 70.41%-114.06%, with relative standard deviations of 0.76%-15.47%. In comparison with previous methods, the new procedure has the advantages of simple sample preparation and higher sensitivity.