ASE提取GC-μECD法测定土壤中的20种有机氯农药

Determination of residues of twenty kinds of organochlorine pesticides in soils with ASE technology and GC coupled with electron capture detector

采用加速溶剂萃取,弗罗里硅土净化,DB-5毛细管柱分离,用微电子捕获检测器(GC-μECD)测定了土壤样品中20种有机氯农药。结果表明,20种有机氯农药均能实现分离,在0.2～500μg/L浓度范围内,均具有良好的线性范围,相关系数均在0.995以上,精密度RSD在1.5%～2.8%(n=6)。以西安周边一农田土壤为例,指示剂TCMX以及PCB191的加标回收率为75.8%～105.5%和81.0%～120%(n=5),总六六六(α-六六六,β-六六六,γ-六六六和δ-六六六)浓度为(5.0±0.2)ng/g,总DDT(p,p'-DDE,p,p'-DDD和p,p'-DDT)浓度为(40.1±0.3)ng/g,均达到了土壤国家一级标准。

The organochlorine pesticides were extracted by accelerated solvent extraction （ASE） and puff- fled by Florisil column and then analyzed by GC coupled with electron capture detector. The determination of 20 organochlorine pesticides in soils was studied. Results showed that the 20 organochlorine pesticides were separate well and a linear calibration curve in the range of 0.2 - 500 μg/L was found with high correlation coefficient （R2 〉 0. 995）. A ease study showed that the recoveries of the spiked TCMX and PCB191 were 75.8 % - 105.5 % and 81.0% - 120% （ n = 5） respectively. The total HCHs and DDTs in the test soil samples are （5.0±0.2） ng/g and （40.1 ±0.3） ng/g,both lower than the guideline of first level （50 ng/g） according to national environmental quality standards for soils of China.