卧龙自然保护区土壤中有机氯农药的来源分析

The Source Analysis for Organochlorine Pesticides in Wolong Natural Reserve Soils

为了判断清洁地区有机氯农药的来源，选择四川西部山区卧龙自然保护区高海拔点位的土壤样品，利用GC-HRMS方法测定有机氯农药的残留量，卧龙土壤中ω（HCHs）和ω（DDTs）分别为（0．42±0．23）和（0．51±0．35）ng／g，比典型污染土壤低1～2个数量级．利用聚类分析方法对浓度归一化数据进行分析，结果表明：卧龙土壤中HCHs的化学组成特征与典型污染土壤不同，而与典型大气样品相似；DDTs的组成特征在典型土壤和大气中没有稳定的显著差异．结合有机氯农药的浓度水平、空间分布和物理化学性质进行分析，结果表明，大气传输过程的贡献可能是卧龙地区生态系统中HCHs以及其他有机氯农药的主要来源。

In order to investigate the sources of OCPs in pristine area, soil samples were collected at high altitudinal sites in Wolong Natural Reserve in western mountain areas of Sichuan Province. Typical OCPs were measured by GC-HRMS. The concentrations of HCHs and DDTs were （0.42 ±0.23） ng/g and （0.51 ± 0.35） ng/g, respectively, 1 to 2 orders of magnitude lower than typical polluted soils. The cluster analysis method was then used based on the normalized compositional data, to investigate the sources of OCPs in this area. It was revealed that the isomeric composition of HCHs in the soil samples was similar to that in the typical air samples, rather than the typical polluted soils. However, there was no distinct difference in DDTs＇ compositions between the typical soils and the typical air samples. Considering the concentration level, the spatial distribution, and the physicochemical properties of the target HCHs isomers, it indicates that atmospheric transport may be the major source of HCHs and DDTs in the mountain soils of Wolong.