固相萃取-毛细管气相色谱法测定枇杷花中有机氯农药残留量

建立了枇杷花中有机氯类农药残留量的固相萃取-毛细管气相色谱(SPE-CGC)分析方法。对采自福建蒲田等12地的枇杷花中六六六(4种异构体)、滴滴涕(4种异构体)、五氯硝基苯共9种有机氯农药的残留量进行了测定。样品采用丙酮超声波提取,浓缩后过Florisil固相萃取小柱净化,洗脱剂为V(正己烷)∶V(丙酮)100∶1。用DB-1701弹性石英毛细管气相色谱柱分离样品,微电子捕获检测器进行检测。9种有机氯农药的峰面积与其质量浓度均有良好的线性关系,相关系数均大于0.999,最低检测限为0.016~0.125μg/L,样品的加标回收率为85.4%~106.9%,相对标准偏差为1.8%~9.8%。该方法能够满足农药残留检测的要求。

Determination of residues of organochlorine pesticides in flowers of Eriobotrya japonica L. by solid-phase extraction and capillary gas chromatography

A method for the determination of 9 organochlorine pesticide residues including α-benzene hexachloride (BHC), β-BHC, γ-BHC, δ-BHC, p,p′-dichloro-diphenyl-dichloroethylene (pp′-DDE), p,p′-dichloro-diphenyl-dichloroethane (pp′-DDD), o,p′-dichloro-diphenyl-trichloroethane (op′-DDT), pp′-DDT, Pentachloronitrobenzene (PCNB) in flowers of Eriobotrya japonica L. from different places of production by solid-phase extraction and capillary gas chromatography was developed. The organochlorine pesticides were extracted from samples with acetone by ultrasonic and cleaned up by florisil solid-phase extraction column with n-hexane-acetone (100∶1, V/V). Then, the extract was separated on a capillary column (30 m×0.25 mm i.d.×0.25 μm) and detected by a micro-electron capture detector. The good linearity was obtained for 9 organochlorine pesticides (r>0.999). The detection limits were between 0.016 and 0.125 μg/L. The recoveries were between 85.4% and 106.9%, and relative standard deviations were 1.8%～9.8%. The method is simple, reproducible and accurate and suitable for analysis of pesticide residues.