不同进样溶剂对有机氯农药测定的影响研究

Effect of Different Solvent on Organochlorine Pesticides Detected

在实际操作中,水、土壤及沉积物中有机氯农药的测定需要进行前处理,二氯甲烷、正己烷是普遍使用的溶剂,而标准物质考核样品溶剂为甲醇。采用了气相色谱-质谱的方法研究了不同溶剂对有机氯农药(α-HCH、β-HCH、γ-HCH、δ-HCH、p,p′-DDE、p,p′-DDD、o,p′-DDT、p,p′-DDT)测定的影响。结果表明,不同溶剂对待测物质的响应值是有差异的,但保留时间不变,且随着待测物浓度的增加,这种溶剂效应对大部分待测物的作用减少;溶剂的极性对有机氯农药的响应值有显著的影响,甲醇溶剂中待测物的响应值低于其他两种溶剂相;甲醇标准物质可用二氯甲烷配制,测定值满足在推荐值之内。

During the actual operation, the sample from water, soil and sediments should be pretreatment to determinate the organochlorine pesticides （ α -HCH,β-HCH,γ-HCH,δ-HCH, p, p＇-DDE, p, p＇-DDD, o, p＇-DDT, p, p＇-DDT）. And n-hexane and dichloromethane were most popular extractive, but methanol was used in standardYmaterial. The effects of different solvents on the response of organochlorine pesticides were studied by Gas chromatography-mass spectrometry（ GC-MS）. The results showed that the polarity of the injection solvents had obvious effects on gas chormatographic responses in the determination of organochlorine pesticide, however, the retention time didn’ t change. With constration of organochlorine pesticides increasing, the solventYeffect in some organochlorine pesticides reduced. Compared with n-hexane and dichloromethane, methanol is strongest polar solvents among them and resulted in. the lowest response.