上海崇明岛农田土壤中有机氯农药残留特征

Characteristics of Organochlorine Pesticide Residues in Agricultural Soil of Chongming Island in Shanghai

为研究崇明岛农田土壤中有机氯农药(OCPs)的残留特征,于2008年7月采集崇明岛农田表层土壤30个.利用加速溶剂萃取仪(ASE)萃取,使用气相色谱-电子捕获检测器(GC-μECD)分析.结果表明,在采集的土壤样品(干重)中,OCPs的含量范围为3.11～117.47 ng.g-1(平均值26.25 ng.g-1);主要组分DDTs和HCHs的含量范围分别为0.14～77.89 ng.g-1(平均值15.80 ng.g-1)和1.14～22.43 ng.g-1(平均值4.52 ng.g-1),另外六氯苯(0.23～11.63 ng.g-1)、艾氏剂(0.03～0.75ng.g-1)、环氧七氯(0.05～1.44 ng.g-1)、狄氏剂(0.05～5.33 ng.g-1)、异狄氏剂(ND～14.66 ng.g-1)和灭蚁灵(0.03～10.58ng.g-1)都有检出.DDTs已经大部分降解为DDD和DDE,并以DDE为主(约64.7%),现存的DDTs主要是早期使用的残留.HCHs的4种同分异构体都有检出,α-HCH(约48.1%)和β-HCH(约33.4%)的含量最多.与大棚种植和传统露天种植相比,集约化的农场种植OCPs的残留更高.

Thirty surface soil samples were collected to investigate the residue concentrations of organochlorine pesticides （OCPs） in agricultural soil of Chongming Island in July 2008. Those samples were extracted using accelerated solvent extraction （ASE） and determined by gas chromatography with an electron capture detector （ GC-μECD）. Results showed that the concentrations of OCPs （ dry weight） ranged between 3.11-117.47 ng·g-1, with mean value of 26.25 ng·g-1. Two major contaminants of OCPs were DDTs and HCHs, the concentration of which varied from 0. 14 ng·g-1 to 77.89 ng·g-1 and from 1. 14 ng.g-l to 22.43 ng·g-1 , respectively. At the same times, hexachlorobenzene （0. 23-11.63 ng·g-1）, aldrin （0. 03-0. 75 ng·g-1 ）, heptaehlor epoxide （0. 05-1.44 ng·g-1）, dieldrin （0.05-5.33 ng·g-1 ） , endrin （ ND-14.66 ng·g-1 ） and mirex （0. 03-10. 58 ng·g-1 ） could also be detected. Most of DDTs had been degraded to DDD and DDE, with tae major compounds of DDE （about 64.7% ）, and the recent existed DDT was the residue of early input. All of the four isomers of I-CHs were detected, and the contents of α-HCH （ about 48.1% ） and β-HCH （ about 33.4% ） were the maximum. The highest OCPs residues appeared in the soil of farm cultivation compared to greenhouse cultivation and ordinary open-air cultivation.