巢湖地区农田土壤中有机氯农药的残留及其分布特征

Residues of organic chlorine pesticide and their distribution characteristics in arable land soil of Chaohu Lake region

2010年6月～7月间,对巢湖周边地区农田土壤以网格法进行采样,对其有机氯农药的残留物的组成特征及其分布状况进行研究。结果表明,采样区土壤中检出的有机氯农药浓度为0.11～32.24 ng·g-1,均值为3.71ng·g-1。其中,六六六(HCHs)和滴滴涕(DDTs)的检出率均高达100%,其残留范围分别为0.24～4.58 ng·g-1和0.36～32.24 ng·g-1,其均值分别为1.39 ng·g-1和7.87 ng·g-1。HCHs的组成以β-HCH为主,具体残留量顺序为β-HCH>α-HCH>δ-HCH>γ-HCH;DDTs的组成以DDE和DDD为主,且DDE含量在50%以上。对污染来源进行分析发现,HCHs残留的α/γ值在0.95～3.12之间,DDTs残留的(DDD+DDE)/DDTs的比值大部分都大于0.5,且DDE/DDD的比值大于1。通过与相关数据进行比照,巢湖地区土壤中的有机氯农药的残留量处于相对偏低的水平。

By grid method, soil samples were taken from the arable land of Chaohu Lake region during June and July in 2010. The distribution characteristics and composition of residues of organi,z chlorine pesticide were studied by gas chromatography. The results showed that the total OCPs concentration value was 0.11-32.24 ng-g1, and the average concentration value was 3.71 ng.g^-1. The detection ratios of HCHs and DDTs from samples were 100%. In which, HCHs residues ranged from 0.24 to 4.58 ng.g^-1 with the average concentration of 1.39 ng.g^-1, and DDTs residues ranged from 0.36 to 32.24 ng.g^-1 with the average concentration of 7.87 ng.g^-1. The HCHs residues were mainly composed of β-HCH, in which the order of all the constituents was β-HCH 〉α-HCH〉δ-HCH〉γ-HCH The DDTs residues were mainly composed of DDE and DDD, in which the percentage of DDE was over 50% as the main composition of DDTs residues. The analysis of the pollution resource showed that HCHs residue α/β value ranged from 0.95 to 3.12, The （DDD＋DDE）/DDTs ratio was greater than 0.5 and the DDE/DDD ratio was greater than 1. In contrast with the related data, residue of organic chlorine pesticide in arable land soil of Chaohu Lake area was relatively at a low level.