加压流体萃取气相色谱法测定土壤中三氯杀螨醇

Determination of Dicofol in Soil by Pressurized Fluid Extraction with Gas Chromatography

利用加压流体装置进行萃取,萃取剂为一种体积比为1∶1的丙酮-正己烷混合试剂,建立用带电子捕获器的气相色谱法分析土壤中有机氯农药三氯杀螨醇的方法。土样经冷冻后干燥或者加入干燥剂后用玛瑙研钵进行研磨,经0.25 mm口径筛网处理成0.250 mm(60目)左右的颗粒,再经筛网筛取土样20 g,加入适量硅藻土,转入洗净的萃取池;用体积为1∶1的丙酮正己烷混合试剂进行加压流体萃取,萃取条件为100℃,10.34 MPa。测定土壤中三氯杀螨醇,相关性较好(R=0.9985),灵敏度较高(方法检出限0.00104 mg/kg),精密度较高(相对标准偏差在0.56%~1.40%),精确度较好(回收率在87.0%~110%)。使用本方法测定土壤中的三氯杀螨醇含量,有一定的可靠性,为土壤中新型污染物三氯杀螨醇含量的检测提供了更好的方式。

In this study,pressure fluid device was used for extraction.The extraction agent was a mixture of acetone and n-hexane with a volume ratio of 1∶1.Gas chromatography with electron catcher was used to analyze the organic chlorine pesticide dicofol in soil.The soil sample was frozen and dried or grinded with agate mortar after adding desiccant.The soil sample was processed into 0.250 mm(60 mesh)particles by a 0.25 mm aperture screen,and then 20 g of soil sample was screened through the screen,and an appropriate amount of diatomaceous earh was added and transferred to the cleaned extraction pool.Pressurized fluid extraction was carried out with acetone n-hexane mixed reagent with a volume of 1∶1,and the extraction condition was 100℃and 10.34 MPa.Determination of dicofol in soil with good correlation(R=0.9985),high sensitivity(detection limit of 0.00104 mg/kg),high precision(relative standard deviation between 0.56%and 1.40%),good accuracy(recovery between 87.0%and 110%).Using this method to determine the content of dicofol in soil has certain reliability,and provides a better way for the new pollutant dicofol content in soil detection.