地下河流域土壤中有机氯农药分布及来源分析

为研究有机氯农药在重庆青木关地下河流域土壤中的分布特征及来源,采用GC-μECD对17个代表性表层土壤样品进行分析.结果显示,研究区土壤中OCPs的含量范围是7.29~222.42ng/g,平均值为46.15ng/g.HCHs、DDTs在所有样品中均有检出,HCHs的含量范围是0.55~26.54ng/g,DDTs的含量范围是4.31~213.50ng/g.HCB的检出率达到88%,其含量范围是n.d.~1.78ng/g.研究区土壤中HCHs可能来源于工业HCHs残留和林丹的混合源,且由于环境影响,土壤中HCH的同系物之间发生了明显变化.DDTs主要来源于工业DDTs的非法使用,而非三氯杀螨醇类型的DDTs,并且仍有新的DDTs输入.与国内其他地区同类研究相比,本研究区土壤中HCHs、DDTs的残留水平较低;与国外相关研究相比,研究区内土壤中HCHs和DDTs的含量均高于德国、埃及、罗马尼亚土壤中HCHs和DDTs的含量.

Distribution tendency and source identification of organochlorine pesticides in soils of an underground river catchment

In order to study the distribution tendency and main possible sources of organochlorine pesticides(OCPs) in Qingmuguan underground river catchment in Chongqing,the concentrations of OCPs residues in 17 topsoil samples were measured by gas chromatography equipped with miro-63Ni electron capture detector.The total OCPs concentrations in soils of Qingmuguan ranged from 7.29 to 222.42ng/g with an average value of 46.15ng/g.HCHs and DDTs existed in all samples.The concentrations of HCHs ranged from 0.55 to 26.54ng/g,wihle the concentration of DDTs ranged from 4.31 to 213.50ng/g.The detectable rate of HCB was 88%,and the concentrations of HCB ranged from n.d.to 1.78ng/g.HCHs in study area came from industrial HCHs and lindane,meanwhile,the compositions of HCH isomers has changed significantly under the impact of environment.There were still fresh inputs of DDTs to soils in Qingmuguan underground river catchment,which substantially originated from illegal use of industrial DDTs rather than the dicofol type of DDT.HCB was a kind of persistent organic pollutants which widely existed in soils of Qingmuguan,and mainly being produced by the regional air deposition in recent years.Compared to the similar researches in other areas in China,HCHs and DDTs residues in the soil of Qingmuguan presented low levels.Furthermore,They were higher than those of Germany,Egypt,Romania when compared with parallel researches worldwide.