【摘要】 采用气相色谱(ECD)对滇池周边不同年限大棚土壤中六六六(HCHs)和滴滴涕(DDTs)残留量进行了测定,探讨其残留分布特征。结果表明:(1)大棚种植年限对土壤中残留量影响显著,种植年限长于10年的大棚土壤中HCHs和DDTs的残留量显著高于年限短于10年的大棚,DDTs是有机氯农药(OCPs)的主要组成成分;短于10年的大棚间,土壤中HCHs和DDTs残留量差异不显著。(2)不同土层中,HCHs残留量在土壤剖面上的变化趋势不明显,而DDTs在表层土壤(0～20 cm)中残留量显著高于下层。(3)从HCHs和DDTs的同系物组成来看,HCHs以β-HCH残留量最高,部分样点中p,p′-DDT/(DDD+DDE)比值大于1。可判断HCHs残留主要是过去施用的残留物,而DDTs仍有新的污染输入,有待进一步调查研究。更多还原

【Abstract】 The characteristics of organo-chlorine pesticides(OCPs) were studied under greenhouse soil conditions.In the study,hexachlorocyclohexane(HCHs) and dichlorodiphenyl trichloroethane(DDTs) OCPs were analyzed using gas chromatography equipped with ECD detector.Soil samples were collected from 0,1～5,5～10,10～15 and 15～25 years-old greenhouses at 0～20 cm,20～40 cm and 40～60 cm soil profiles.Based on the study,mean HCHs and DDTs residue significantly increased in soil of green-houses older than 10 years.HCHs and DDTs residues were not significantly different in 0～10 years-old greenhouse soils.DDTs were main component of OCPs residue.The trend in HCHs residue variation was not significantly different in different soil layers.How-ever,DDTs concentration in the 0～20 cm surface soil was significantly higher than that in other soil layers.β-HCH concentration was higher than other HCH isomers in greenhouse soils.This suggested that the source of soil HCHs was residue of past applications.p,p′-DDT/(DDD+DDE) value in some soil samples was greater than one,suggesting that new DDTs were input in some of the greenhouses.更多还原