冻干技术在果蔬中有机氯及多种拟除虫菊酯农药残留检测中的应用

Application of freezing-drying method for determination of organochlorines and pyrethroid pesticides multiresidues in fruits and vegetables

目的：应用冻干技术建立果蔬中有机氯及多种拟除虫菊酯农药残留检测方法。方法：应用冻干技术去除果蔬中的水分,以丙酮-二氯甲烷（1：1）为提取溶剂,经CARB/NH2和Florisl固相萃取柱净化,用GC-ECD测定,峰面积定量。结果：10种农药加标回收率为80.8%-95.4%,相对标准偏差为1.8%-4.8%,最低检出浓度为0.001-0.005 mg/kg（当称样量为5.00 g时）。结论：冻干技术对检测结果影响较小,而且前处理过程中有机溶剂的用量大大减少了,操作简单,检测结果的重现性及方法回收率明显改善,该方法适合果蔬中1种有机氯及9种拟除虫菊酯类农药残留的同时检测,尤其适合大批量农残样品的检测。

Objective：To establish a method for determination of pesticides residues using freezing-drying method.Methods：After drying up by freezing-drying method,the moisture of fruits and vegetables was extracted by the acetone and dichloromethane solvent（v：v=1：1）,then cleaned up with the CARB/NH2 and Florisl solid phase extract column.The residues were detected by GC-ECD and quantified with the area of peak.Results：The recoveries of 10 organochlorines and pyrethroid pesticide multiresidues were 80.8%~95.4%,the RSD 1.8%~4.8%,the minimum detection concentrations 0.001~0.005 mg/kg（as the detection quantity of samples were 5.00 g）.Conclusion：Freezing-drying method slightly affects the result of determination and uses less organic solvent.The method is simple,convenient and suitable for the analysis of the 1 organochlorines and 9 pyrethroid pesticides multiresidues in fruits and vegetables,especially for the analysis of quantities of samples.