湖南省土壤中有机氯农药的残留规律研究

Studies on Residues of Organochloride Pesticides in the Soils of Hunan Province

2004年5月采集了湖南省120个土壤样品,采用AES萃取技术,用GC-MS方法测定了样品中的六氯苯、滴滴涕(DDTs)、氯丹、艾氏剂、狄氏剂、异狄氏剂、七氯和灭蚁灵.结果显示:六氯苯和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、异狄氏剂和七氯均未检出,说明六氯苯和DDTs曾在湖南省广泛施用.w(有机氯农药)平均值为115.3μg/kg,其中w(DDTs)占w(有机氯农药)的96.44%,在全部120个样点中有21.67%的土壤样品的w(DDT)/w(DDE+DDD)大于1,表明DDTs曾是湖南省用于农作物的主要杀虫剂,并且近期仍然有输入.不同使用功能的土壤中有机氯农药的残留量也不同,表现为旱地中的残留量高于水稻田,菜地中以辣椒地的残留量最高,茶场土壤中的残留量最低.

120 samples were collected from Hunan Province in May 2004. The samples were analyzed for Hexaehlorobenzene （HCB）, DDTa （DDT, DDE and DDD）, Chlordane, Aldrin, Dieldrin, Endrin, Heptaehlor and Mire by AES extraction technique and GC-MS method. The results were as follows： the relevance ratio of HCB and DDTs was 100% , the relevance ratio of Chlordane and Mirex was lower, and Aldrin, Dieldrin, Endrin and Heptachlor were not detected. It was shown that HCB and DDTs were used widely in Hunan. The mass fraction average of OCPs was 115.3 μg/kg, in which DDTs was the primary compound in soil samples, accounting for 96.44% of OCPs. Among the 120 sampling sites, 21.67 % soil samples have the ratio of w （DDT）/w （DDE ＋ DDD） greater than 1, and it show that there were still fresh DDTs emitted into Hunan soils. Different functions of soil have different levels of OCPs residue, with the residue in dry land higher than that in rice paddy land, the residue in pepper field highest among vegetable fields, and tea field having lowest residue.