湖南省东北部蔬菜土壤中有机氯农药残留及其组成特征

Residues and Distribution Characters of Organochlorine Pestcides in Vegetable Soil in the Northeast of Hunan

2006年3月,采集湖南省东北部7个地区蔬菜土壤样品,采用GC-ECD检测、GC/MS-MS确证的方法对土壤中20种有机氯农药进行分析,并探讨有机氯农药在蔬菜土壤中的残留现状及组成。结果表明,HCHs和DDTs检出率高达100%,残留量范围分别为0.15～16.80μg·kg-1和6.05～57.91μg·kg-1。OCPs的主要残留物是DDTs,占残留总量的70%以上。绝大部分地区土壤中α-HCH/γ-HCH比值大于1,DDT/(DDE+DDD)比值小于1,表明HCHs和DDTs主要来自于早期的使用,但岳阳和衡阳地区近期可能有新的DDTs农药输入。艾氏剂、狄氏剂、γ-氯丹和环氧七氯也有不同程度的检出。与国内外相关报道相比,HCHs和DDTs残留水平较低。

Soil samples of vegetable soil were collected from seven sites in northeast of Hunan province in March 2006. Twenty kinds of organochlorine pesticides in the samples were analyzed with gas chromatography method. HCHs and DDTs were found widely in all these considered samples and with a range of 0.15-16.80μg·kg^-1 for HCHs and 6.05～57.91 μg· kg^-1 for DDTs, respectively. The DDTs were the main components in residues of organochlorine pesticides, accounting for more than 70% of the total. The ratio of a-HCH/γ-HCH were above 1,0, DDT/（DDE＋DDD） were less than 1.0 in the main parts of regions, indicating that Lindane and DDTs might come from the old usage, but there might be input into environment recently in Yueyang and Hengyang regions. Aldrin, dieldrin, γ-chlordane and heptachlor epoxide were detected with different degree in all the samples. Compared to the reference data, the residual levels of DDTs, HCHs in soil were slighter.