以土壤中六氯环戊二烯、六氯丁二烯、六氯乙烷为研究对象,采用加速溶剂萃取法进行在线净化和萃取,用气相色谱-质谱法测定。将土壤样品10 g与石英砂20 g混合均匀后,加入到装有氟罗里硅土粉1 g和石墨炭黑粉0.2 g的萃取池中,以二氯甲烷-丙酮(4+1)混合液为萃取剂进行萃取。考察了萃取温度、萃取剂、分散剂和土壤pH、TOC等因素的影响,分析了在线净化和离线净化的差异以及复合净化的优势。应用该方法对3个不同土壤样品进行测定,回收率在72.3%~89.0%之间,相对标准偏差(n=7)为7.4%~13%。

Accelerated solvent extraction and on line purification of hexachlorocyclopentadiene, hexachlorobutadiene and hexachloroethane in soil for GC-MS detection were studied in this research. Soil sample (10 g), mixed with silica sand (20 g), was placed in the extract cell with fluorine silica powder (1 g) and graphitized carbon powder (0.2 g); and then the polychlorinated hydrocarbons were eluted by mixture of dichloromethane and acetone (4+1). Influence of temperature, extracting solvent, dispersing agent, pH and TOC content were studied. Difference of on line and off line purification as well as superiority of composite purification were also analyzed in this study. The proposed method was applied to the analysis of 3 different soil samples, giving values of recovery and RSD′s in the range of 72.3%-89.0% and 7.4%-13% respectively.