闽西北水稻土有机氯农药残留特征

采用气相色谱对福建闽西北地区水稻土中有机氯农药(HCHS、DDTS)残留量进行了测定，探讨其残留特征。结果表明：调查区土壤中HCHS和DDTS残留量分别为0.41~9.61 μg/kg和6.51~469.50 μg/kg，土壤HCHS残留量均低于土壤环境质量标准(GB 15618—1995)的一级标准限量值(50μg/kg)，但有23.1%的样点土壤OCPS残留总量高于50 μg/kg。OCPS主要残留物是DDTS。土壤中HCHS异构体的残留特征是β-HCH>r-HCH>α-HCH>δ-HCH，其中HCHS以β-HCH残留最高；土壤DDTS残留特征是pp'-DDT>op'-DDT>pp'-DDD>pp'-DDE，土壤DDT残留以pp′-DDT为主，且pp′-DDT/(DDD＋DDE)大于1，说明DDTS可能有新的污染输入。

Residues Characteristics of Organochlorine Pesticides in the Soil of Rice in FuJian of Northwest

The residue characteristics of organochlorine pesticides (OCPS) were studied under the soil of rice. In the study, hexachlorocyclohexane (HCHS) and dichlorodiphenyl trichloroethane (DDTS) were analyzed using gas chromatography equipped with ECD detector. The results showed that HCHS and DDTS were found widely in all samples and with a range of 0.41-9.61μg/kg and 6.51-469.50 μg/kg respectively. The content of HCHS was much lower than the soil environmental quality standard (GB 15618-1995), and it limits the quantity being worth 50 μg/kg, but 76.9% of samples had a total DDTS residue of less than 50 μg/kg. And the DDTS, which was the main components in residues of organochlorine pesticides, took over 96.2% of the total. The residual characteristics of HCHS isomers in the soil was β-HCH>γ-HCH>α-HCH>δ-HCH, β-HCH concentration was higher than other HCHS isomers. The residual characteristics of DDTS isomers in the soil was pp'-DDT>op'-DDT>pp'-DDE>pp'-DDD, and the pp'-DDT was the main components in residues of DDTS, pp′-DDT/(DDD＋DDE) value in soil was greater than one, this suggested that the new DDTS were input in the soil of rice.