气相色谱法测定地表水中拟除虫菊酯类农药残留

建立了气相色谱检测地表水样中痕量氯氟氰菊酯、氯氰菊酯、氰戊菊酯和溴氰菊酯农药残留的分析方法。水样经环己烷液液萃取、无水硫酸钠过滤,再用N-丙基乙二胺和无水硫酸镁净化,用氮气吹干浓缩,再用正己烷溶解,离心分离后取上清液进样,以气相色谱法测定4种拟除虫菊酯的含量。4种拟除虫菊酯化合物的质量浓度在5~200μg/L范围内与色谱峰面积成良好的线性关系,相关系数均大于0.999,方法检出限为0.03~0.09μg/L,模拟水样的平均加标回收率为98.0%~104.5%,相对标准偏差为0.89%~6.44%(n=6)。该方法操作方便、快速,结果准确、可靠,有机溶剂用量少,适用于水中拟除虫菊酯类农药残留的测定。

Determination of pyrethroid pesticide residues in surface water by gas chromatography

A gas chromatograph method was established to determine four kinds of pyrethroid pesticides such as cyhalothrin,cypermethrin,fenvalerate and deltamethrin in surface water samples at trace levels.Water samples were extracted by cyclohexane,the extraction solution was filtered through anhydrous sodium sulfate,and the purified with N-propyl ethylenediamine and anhydrous magnesium sulfate,after being concentrated by nitrogen,dissolved with n-hexane,after centrifugal separation,the supernatant was used to determine the content of pyrethroid by gas chromatography.The calibration curves were linear in the range of 5-200μg/L for target compounds with correlation coefficients all more than 0.999.The detection limits were 0.03-0.09μg/L.The average recoveries were 98.0%-104.5%with RSDs of 0.89%-6.44%(n=6).This method is suitable for the determination of pyrethroid pesticides in surface water due to its easy operation,fast,accurate,reliable,less solvent dosage.