三油酸酯-半渗透膜采样装置对有机氯农药的富集作用

ACCUMULATION KINETICS OF ORGANOCHLORINATED PESTICIDES BY TRIOLEIN-CONTAINING SEMIPERMEABLE MEMBRANE DEVICES

在实验室流水条件下研究了林丹、艾氏剂、环氧七氯、4 ,4′ 滴滴涕及六氯苯在三油酸酯 半渗透膜采样器 (SP MDs)中的富集。所研究的 5种有机氯农药在SPMDs中富集迅速 ,动力学过程可以用线性关系描述 ,2 0d后富集系数达到 15 0 0— 180 0 0。当暴露于接近天然水体浓度时 (2 μg/L) ,富集量能够达到对生物标记物研究制样量的要求 ,富集量大小顺序为六氯苯 >4 ,4’ 滴滴涕 >七氯环氧 >艾氏剂 >林丹 ,与有机氯化合物的脂 /水分配系数成正相关。初步研究结果表明SPMDs可以用来作为生物标记物测试的样品前处理手段 ,或替代水体生物进行微量或痕量有毒有机污染物的生物毒性监测。

There is a clear need for rapid,easy to use,effective and low-cost integrative methods that allow not only the direct monitoring of the fate and concentrations of trace level of chemical-contaminant mixture in the environment,but also an assessment of the hazard these chemicals pose to aquatic organisms and human health. Membrane-based passive samplers seem to be a promising tool for the time-integrated monitoring of hydrophobic pollutants in aquatic ecosystems. In these devices the uptake of chemicals is based on the process of passive partitioning of a compound between water and a lipophilic solvent enclosed in a semi-permeable polymeric membrane. Thus,the passive samplers can be used as indicators of bioavailability of chemical pollutants. In this research,uptake kinetics of five organochlorinated pesticides,i. e. chlorines hexachlorobenzene,lindan,aldrin,heptachlor epoxide and 4,4’-DDT,by triolein-containing semipermeable membrane devices(SPMDs)was investigated in a laboratory continuous flow system. Results showed that the concentration kinetics of the analytes by the SPMDs were linear during the exposure period of 20-d and the concentration factors were in the range of 1500—18000. At par per billion levels,the bioconcentration factors were positively corrected with the octanol/water partitioning coefficients. We conclude that SPMDs technology can be used to accumulate lipophilic organochlorinated pesticides from aquatic environment in a similar way as aquatic biota to a level sufficient for further biomakers research.