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目的:采用改良的QuEChERS法联合气相色谱-质谱技术,建立一种快速检测人参提取物中25种农药残留的分析方法。方法:样品以乙腈提取,经氯化钠、无水硫酸镁盐析后,上清液加入乙二胺-N-丙基硅烷和石墨炭黑分散固相萃取剂进行净化,并采用基质匹配标准曲线法进行定量分析。结果:异狄氏醛,p,p’-滴滴涕和甲氧滴滴涕在人参提取物中表现出相对较强的基质效应(ME>130%),而对硫磷则呈显著的基质效应(ME>150%),采用基质匹配标准曲线法校正后,25种农药在0.01~1 mg·L-1线性关系良好,相关系数r>0.995 4,3个添加水平(0.1,0.5,1.0μg·g-1)的平均回收率在81.8%~110.7%,RSD均<15%,定量限(LOQ)在3~48μg·kg-1。结论:该方法能有效减少基质效应,并具有良好的准确度、重复性和灵敏度,适合于人参提取物中多农药残留的测定。
OBJECTIVE: To establish a rapid method for the determination of 25 pesticide residues in ginseng extract by a modified QuEChERS method combined with gas chromatography-mass spectrometry. Methods: Samples were extracted with acetonitrile, salted with sodium chloride and anhydrous magnesium sulfate, the supernatant was added with ethylenediamine-N-propylsilane and graphite carbon black dispersed solid-phase extractant for purification, and the matrix matching standard Curve method for quantitative analysis. Results: Isodinaldehyde, p, p’-DDT and methionine DDT showed a relatively strong matrix effect (ME> 130%) in ginseng extract, while parathion showed a significant matrix effect (ME> 150%). After calibration by matrix matching standard curve, the linear relationship of 25 pesticides at 0.01-1 mg · L-1 was good with the correlation coefficient r> 0.995 4, 3 added levels (0.1, 0.5, 1.0 μg · g- 1) was 81.8% ~ 110.7%. The RSDs were all less than 15% and the limit of quantification (LOQ) was between 3 ~ 48μg · kg-1. Conclusion: The method can effectively reduce the matrix effect, and has good accuracy, repeatability and sensitivity, and is suitable for the determination of multi-pesticide residues in ginseng extract.