工业企业棕地土壤中84种多氯联苯的测定

Determination of the 84 Kinds of Polychlorinated Biphenyls in the Brownfield of Industrial Enterprises

由于多氯联苯易被土壤有机质吸附,工业企业棕地土壤可能成为多氯联苯的新排放源,因此建立该类土壤中多氯联苯适用的分析方法尤为重要。本文将US EPA8082方法与3665方法相结合,将高锰酸钾加入到提取体系,建立了正己烷-丙酮-高锰酸钾体系提取,硅胶净化,GC/ECD分析,GC/MS验证的方法测定工业企业棕地土壤中84种多氯联苯。研究发现,高锰酸钾的加入可以祛除部分元素硫,同时将部分共萃物氧化为盐类,使得硅胶净化基线噪声大大降低。通过对不同类型工业企业棕地土壤样品的加标回收、精密度试验等对方法进行评价,84种多氯联苯的方法检出限为5.0～65.0 ng/kg,加标回收率为62.19%～117.96%,相对标准偏差（RSD,n=6）为0.24%～24.67%。该方法抗基体干扰强、成本低,可用于工业企业棕地土壤中84种多氯联苯的分析测定。

Industrial Brownfield may become a new exhaust resource of Polychlorinated Biphenyls （PCBs） because it is absorbed easily by organic matter of soil, so it is important to establish an effective determination method for PCBs. Currently PCBs together with interference is extracted into solvent based on its physical property, but trace or ultra trace analysis for samples is very difficult because of interference in solvent. A method for determination of 84 PCBs in Brownfield was established in this paper by combining US EPAS082 with 3665 method, establishing hexane - acetone - KMnO4 extraction system, purifying with silica gel, determining by GC/ECD and verifying by GC/MS. The result of research indicate that KMnO4 can get rid of sulfur and oxidize some interference in solvent into salts, and the noise of curves purified with silica reduce clearly. According to the appraising of determining types of soil sample, precision testing, and so on, the detection limits of the method for the 84 PCBs ranged from 5.0 ～ 65.0 ng/kg, and the average recoveries ranged from 62.19% ～117.96% with precision of 0.24% ～ 24.67%, and the method can be applied to the routine analysis of PCBs in Brownfield samples with the advantages of good anti - interference of matrix effect and low cost.