液液萃取-气相色谱法测定水中有机氯的方法研究

目的]建立液液萃取？气相色谱法定量分析水中有机氯的方法。方法]通过萃取溶剂的选择、水样的配制、萃取间隔时间的选择等单因素试验,优化水样中有机氯的萃取条件。结果]液液萃取的最佳试验条件为：以正己烷∶石油醚=60∶30（V/V）作萃取溶剂,不加有机改性剂,连续萃取3次,合并萃取液并浓缩至1 ml。该方法回收率在85%105%,最小检出浓度为0.0200.075μg/L,相对标准偏差为0.9%6.5%,与固相萃取效果相当。结论]液液萃取？气相色谱法定量分析水中有机氯具有快速、灵敏、准确、简单、回收率高等优点,能够满足残留检测的要求。

Analytical Method for Organochlorine Pesticides in Water by LLE-GC

Objective] The aim was to establish a method for the determination of organchlorine pesticides in drinking water by Liquid-Liquid extraction(LLE),gas chromatography.Method] The inspection conditions was optimized through the single factor experiments of the selection of LLE solvent,preparation of water samples and extraction time interval.Result] The optimal conditions of LLE were showed as following:taking n-hexane∶petroleum ether = 60∶30(V/V) as solvent,without organic modifier,extraction 3 times continuously,mixing the extraction liquid and enriching it to 1 ml.The recoveries of every compounds extracted by in this method was 85%-105%,the minimal detection concentration was between 0.02-0.075 μg/L,the relative standard deviation ranged from 0.9% to 6.5%.The effect of LLE was almost the same as SPE.Conclusion] The analytical method for organochlorine pesticides in water by LLE-GC got the advantage of rapid,sensitive,accurate,simple,high recovery rate.It satisfied the requirement of residue testing.