全自动固相萃取-气相色谱法测定生活饮用水中12种有机磷农药

Determination of 12 organophosphorus pesticides in drinking water by automatic solid-phase extraction and gas chromatography

目的建立同时测定生活饮用水中12种有机磷农药全自动固相萃取-气相色谱法。方法含有机磷农药水样用HCl调节pH值为6~7后,采用全自动固相萃取,经HLB固相萃取柱富集净化,用二氯甲烷洗脱,40℃下浓缩至0.2 ml,加入5 ml丙酮浓缩至1 ml,定量注入DB-1701毛细管色谱柱,各有机磷农药成分在色谱柱上逐一分离,火焰光度检测器(FPD)检测。结果水中敌敌畏、甲拌磷、内吸磷、稻瘟净、乐果、毒死蜱、甲基对硫磷、马拉硫磷、杀螟硫磷、对硫磷、水胺硫磷、丙溴磷12种有机磷农药能有效地分离,线性关系良好,相关系数(r)均>0.999,方法检出限为0.041μg/L~0.34μg/L,低、中、高浓度水平加样回收率为74.1%~112.0%,相对标准偏差为0.77%~9.19%。结论该方法适用于同时测定生活饮用水中12种有机磷农药,操作简便,分离效率高,易于基层单位普及推广。

Objective To establish a method for the simultaneous determination of 12 organophosphorus pesticides in drinking water by automatic solid-phase extraction and gas chromatography. Methods The water samples containing organophosphorus pesticides were adjusted to 6-7 p H value by HCl. The organophosphorus pesticide residues in drinking water were extracted automatically by HLB solid phase extraction column with dichloromethane. The collected solution was dried to 0. 2 ml at 40 ℃and dried to 1 ml after adding 5 ml acetone. Then the collected solution was injected quantitatively into DB-1701 capillary column. The components of organophosphorus pesticides were separated one by one on the column,and then detected by flame photometric detector( FPD). Results The 12 organophosphorus pesticides of dichlorvos,phorate,demeton,isoprothiolane,dimethoate,chlorpyrifos,methyl parathion,malathion,fenitrothion,parathion,hydrocarbophos and profenofos in water were separated effectively. Good linearities of the method were obtained with correlation coefficient( r) ≥ 0. 999. The limits of detection for all organophosphorus pesticides ranged from 0. 041 μg/L to 0. 34 μg/L. The recovery rate of each organophosphorus pesticides at low,medium and high concentrations were respectively within 74. 1%-112. 0% and the relative standard deviations were within 0. 77%-9. 19%. Conclusion This method is suitable for the simultaneous detection of 12 organophosphorus pesticides in drinking water. It is easy to operate with high separation efficiency and easy to popularize in grass-roots unit.