福州地区不同土地利用类型土壤中六六六和滴滴涕的残留特征

采集福州地区106个表层土壤样品,运用气相色谱-电子捕获检测器(GC-μECD),分析了不同土地类型土壤中六六六(HCHs)和滴滴涕(DDTs)残留水平、组成特征及来源。结果表明,福州土壤HCHs总浓度为0.581～66.9μg·kg-1,DDTs总浓度为0.782～110μg·kg-1。不同土地利用类型土壤中HCHs残留量为未利用地>水田>旱田>草地>林地。4种HCHs异构体中,草地、旱田和林地土壤中分别以α-HCH、β-HCH和γ-HCH相对含量最高,水田和未利用地土壤中δ-HCH含量最高。不同土地利用类型土壤中DDTs残留量为未利用地>旱田>水田>林地>草地,除未利用地土壤中相对含量最高的同系物是p,p′-DDD外,其余4种类型土壤中均是p,p′-DDE相对含量最高。来源分析表明,福州可能有林丹(主要成分为γ-HCH)输入,草地可能还有工业HCHs的输入;未利用地、旱田、林地土壤还存在新的DDTs输入,水田和草地土壤近期无工业DDTs输入;旱田、水田、未利用地可能还有少量三氯杀螨醇的使用或输入。

Residues Characteristics of HCHs and DDTs in Soils Under Different Land Utilizations in Fuzhou Region, China

106 soil samples from different land use pattern were collected in Fuzhou and the concentrations of HCHs and DDTs in the soils were determined by GC-μECD. The concentrations of ΣHCHs and ΣDDTs in soils were in the ranges of 0.581~66.9 μg·kg-1 and 0.782~110 μg·kg-1 respectively. The residue level of HCHs in different lands was as follows:unused land>paddy field>dry land>grassland>woodland. The highest relative content was α-HCH, β-HCH and γ-HCH in grassland, dry land and woodland, respectively, and the highest was δ- HCH in paddy field and unused land. The residue level of DDTs was as follows:unused land>dry land>paddy field>woodland>grassland. The highest relative content was p, p′-DDD in unused land while p, p′-DDE in the other four soils. Source analysis indicated that new input of lindane might exist in Fuzhou and industrial HCHs input in grassland. Newly input of DDTs might exist in unused land, dry land and wood- land while no input of industrial DDTs were found in paddy field and grassland. Little amount use or input of dicofol might exist in dry land, paddy field and unused land.