Abstract：
Organochlorine pesticides show biological toxicity and their degradation typically takes many years. Previous studies of agrochemical-contaminated areas have mainly focused on limited target compounds, and emerging pollutants in soil have been overlooked. In this study, we collected soil samples from an abandoned agrochemical-contaminated area. Target analysis and non-target suspect screening by gas chromatography coupled with time-of-flight mass spectrometry were combined for qualitative and quantitative analysis of organochlorine pollutants. Target analysis showed that dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethylene (DDE), and dichlorodiphenyldichloroethane (DDD) were the main pollutants. With concentrations between 3.96 × 106 and 1.38 × 107 ng/g, these compounds posed significant health risks at the contaminated site. Non-target suspect screening identified 126 organochlorine compounds, most of which were chlorinated hydrocarbons and 90% of the compounds contained a benzene ring structure. The possible transformation pathways of DDT were inferred from proven pathways and the compounds identified by non-target suspect screening that had similar structures to DDT. This study will be useful for studies of the degradation mechanism of DDT. Semi-quantitative and hierarchical cluster analysis of compounds in soil showed that the distribution of contaminants in soil was influenced by the types of pollution sources and distance to them. Twenty-two contaminants were found in the soil at relatively high concentrations. The toxicities of 17 of these compounds are currently not known. These results improve our understanding of the environmental behavior of organochlorine contaminants in soil and are useful for further risk assessments of agrochemical-contaminated areas.
摘要：
有机氯农药显示出生物毒性，其降解通常需要很多年。以前对农业化学污染地区的研究主要集中在有限的目标化合物上，土壤中出现的污染物被忽视了。在这项研究中,我们从一个废弃的农业化学品污染地区收集了土壤样本。通过气相色谱与飞行时间质谱联用的目标分析和非目标可疑筛查相结合，对有机氯污染物进行定性和定量分析。目标分析表明,二氯二苯基三氯乙烷(DDT),二氯二苯基二氯乙烯(DDE),主要污染物为二氯二苯基二氯乙烷(DDD)。浓度在3.96×106和1.38×107ng/g之间，这些化合物在受污染的地点构成了重大的健康风险。非目标可疑筛查确定了126种有机氯化合物，其中大部分是氯代烃，90%的化合物含有苯环结构。DDT可能的转化途径是从已证实的途径和通过非靶标可疑筛选鉴定的具有与DDT相似结构的化合物中推断出来的。本研究对DDT降解机理的研究具有一定的参考价值。对土壤中化合物的半定量和层次聚类分析表明，污染物在土壤中的分布受污染源类型和与它们的距离的影响。在土壤中发现了相对较高的22种污染物。这些化合物中的17种的毒性目前是未知的。这些结果增进了我们对土壤中有机氯污染物的环境行为的了解，并可用于进一步评估农药污染地区的风险。
