湘江流域土壤中有机氯农药的残留规律

2004年5月采集了湘江流域51个样品，用AES萃取技术，使用GC-MS方法测定了样品中的六氯苯(HCB)、滴滴涕(DDTs)、氯丹、艾氏剂、狄氏剂、异狄氏剂、七氯和灭蚁灵等有机氯农药(OCPs). 结果表明:HCB和DDTs的检出率为100%，氯丹和灭蚁灵的检出率较低，艾氏剂、狄氏剂、异狄氏剂和七氯未检出，说明HCB和DDTs曾在湘江流域广泛施用. w(OCPs)平均值为145.49 μg/kg，其中w(DDTs)占w(OCPs)的90.9%，且有些土壤样品中w(DDT)/w(DDE+DDD)较大，说明DDTs曾作为湘江流域的主要杀虫剂施用过，并且近期仍然有输入. 农药残留量与农药的施用量成正比，农药施用量高的衡阳地区，其土壤中的农药残留量最高. 不同使用功能的土壤中有机氯农药的残留量不同，表现为旱地中的残留量高于水稻地，蔬菜地中以辣椒地的残留量最高. 

Studies on Residues of Organochloride Pesticides (OCPs) in the Soils of Xiangjiang River Valley

51 samples were collected from Xiangjiang River valley in May 2004. The samples were analyzed for Hexachlorobenzene (HCB), DDTs(DDT, DDE and DDD), Chlordane, Aldrin, Dieldrin, Endrin, Heptachlor and Mire by gas chromatography with mass selective detection (GC-MS). The results were as follows: the detection rates of HCB and DDTs were 100%, the detection rates of Chlordane and Mirexwere lower, Aldrin, Dieldrin, Endrin, Heptachlor were undetected. It was shown that HCB and DDTs were used widely in Xiangjiang River valley. The mass fraction average of OCPs was 145.49 μg/kg, and DDTs were the primary compounds in soil samples, accounting for 90.9% of OCPs. The high ratio of w(DDT)/w(DDE+DDD) in some region possibly indicated that DDTs were mostly used as insecticide and there were still fresh DDTs emitted into Xiangjiang River valley. The pesticide residue is also in direct proportion to the use level of pesticides. For an example, the pesticide residue level is highest in soil samples in Hengyang area where the use of pesticides was higher. The pesticide residue of OCPs was different in soils of different functions. It was shown that the pesticide residuein dry land was higher than in paddy land and the highest pesticide residue of OCPs was found in pepper land among vegetable lands.