QuEChERS联用气相色谱法同时测定枸杞中21种拟除虫菊酯农药残留

Simultaneous Determination of 21 Kinds of Pyrethroid Pesticide Residues in Lycii Fructus by QuEChERS Method with Gas Chromatography

目的建立QuEChERS联用气相色谱同时测定枸杞中21种拟除虫菊酯农药残留的方法。方法针对枸杞基质,优化QuEChERS技术中净化填料的用量,并考察所有目标农药的基质效应。采用DB-35毛细管色谱柱分离待测物,采用电子捕获检测器(ECD)测定,以保留时间定性,以基质匹配标准曲线定量。结果21种拟除虫菊酯在质量浓度为0.010~1.0μg/ml范围内呈现良好的线性关系,相关系数均大于0.9990,方法定量限在0.005~0.010mg/kg之间。空白样品3个水平的加标回收率均在80.14%~116.38%之间,相对标准偏差在0.38%~8.76%范围内。结论此法可应用于枸杞及枸杞制品中21种拟除虫菊酯农药残留检测和定量分析。

Objective To establish a method for simultaneous determination of 21 kinds of pyrethroid pesticide residues in Lycii Fructus by QuEChERS method coupled with gas chromatography(GC).Methods According to the matrix of Lycii Fructus,the amount of purification fillers in QuEChERS method was optimized and the matrix effects of all target compounds were evaluated.The samples were separated by DB-35 capillary column and determined by electron capture detection(ECD).Retention time was used for qualitative analysis and matrix matched calibration standards curve was used for quantitative analysis.Results There were good linear relationships in the range of 0.010-1.0μg/ml for the pyrethroid pesticides and the correlation coefficients were greater than 0.9990.The quantitative limits of 21 pyrethroid pesticides were 0.005-0.010 mg/kg.The recoveries of spiked samples at 3 levels range were 80.14%-116.38%,and the RSDs were 0.38%-8.76%.Conclusion The method has been successfully applied for the determination and quantitative analysis of 21 kinds of pyrethroid pesticide residues in Lycii Fructus and Lycii Fructus products.