GC-ECD法同时测定土壤中20种有机氯农药的方法

Research on simultaneous determination of twenty organochlorine pesticides in soil

目的:通过优化实验条件,建立快速、高效、准确的同时测定土壤中20种有机氯农药(organochlorine pesticides,OCPs)的气相色谱-电子捕获检测器(GC-ECD)检测法,为土壤中OCPs的准确测量和风险评估奠定基础。方法:通过加标回收率实验,确定土壤样品最佳浸泡时间和提取时间;通过GC-ECD检测法同时测定土壤中20种OCPs对所建立的方法进行确认。结果:最佳浸泡时间为10 h,最佳提取时间为6 h。20种OCPs标准曲线方程线性相关系数为0.9992~0.9999,样品中20种OCPs的检出限为0.015~0.061 ng/g,加标回收率为79.7%~93.3%,方法相对标准偏差(relative standard deviation,RSD)为4.41%~7.87%,分离度良好。结论:该方法检出限低,精密度和回收率较高,结果准确,在一定程度上缩短了样品分析周期,适用于土壤中OCPs残留检测分析。

Objective：To establish a rapid, high - efficient and aceurate GC - ECD method for detennining twenty organoehlorine pesticides （OCPs） in soil by optimization of experimental conditions, so as to lay the foundation for accurate measurement and risk assessment of OCPs in soil. Methods：The optimal soaking time and extmetlng time of soil were determined by recovery experiments and the feasibility of GC -ECD meth- od was verified by further experimentation. Results：The optimal soaking time was 10h, and the optimal extracting time was 6h. The coefficient of correlation of standard curve equation of twenty OCPs ranged between 0.9992 ～ 0. 9999 ; the detection limit of OCPs determination in the sample ranged between 0.015 ～ 0.061 ng/g, and the recoveries ranged between 79.7 % - 93.3 % ; the relative standard deviation of OCPs ranged be- tween 4.41% ～ 7.87 %. The resolution was good. Conclusion： GC - ECD method features low detection limit, high precision, high accuracy and short analysis time, so it is great for application in analyzing the OCPs residues in soil.