气相色谱法同时测定蔬菜中24种有机磷农药残留

Determination of 24 organophosphorus pesticide residues in vegetable by gas-chromatography

建立了蔬菜中24种有机磷类农药残留气相色谱同时分析的方法。样品用含0.1%乙酸的乙腈提取,净化采用分散固相萃取的方式：在提取液中加入C18（ODS）、石墨炭黑、PSA等吸附剂粉末进行净化,采用DB-1701（30 m×0.32 mm×0.25μm）毛细管柱分离,FPD（P）检测。24种农药的质量分数在0.002～0.05 mg/kg时,回收率在80.1%～102.1%之间、RDS为1.4%～5.1%。各农药的检测限为：三硫磷、三唑磷为0.004 mg/kg、苯硫磷为0.01 mg/kg,其它21种为0.002 mg/kg。

A gas chromatographic method!has been developed for the determination of 24 organophosphorus pesticide residues in vegetable.The pesticide residues were extracted from vegetable samples with acetic acid/acetonitrile（1∶999 v/v）.In the purified process,the extracts were cleaned up with the addition of C18 （ODS）、 GCB and PSA,separated on a capillary column DB-1701（30 m×0.32 mm×0.25 μm） and detected by FPD（P）.In the range of 0.002～0.05 mg/kg,recoveries（n=6） were 80.1%～102.1%,with RSDs of 1.4%～5.1%.The detection limits of carbophenothion and triazophos are 0.004 mg/kg, EPN is 0.01 mg/kg, and the other 21 pesticides are 0.002 mg/kg. The method has the advantages of simplicity, repeatability and sensitivity.