Oh So-Rin, Kim Jung-Kon, Lee Min-Jung, Choi Kyungho
Institute of Health and Environment, Department of Environmental Health, School of Public Health, Seoul National University, 28 Yunkeon, Chongro, Seoul 110-799, Korea.
Environ Toxicol. 2008 Apr;23(2):211-7. doi: 10.1002/tox.20325.
Sodium thiosulfate is recommended by U.S. Environmental Protection Agency for dechlorination of the effluent samples containing residual chlorines before the toxicity testing. For samples contaminated with residual chlorine and metals, e.g., Cd(II), Cu(II) and Ni(II); however, metal toxicity as measured with Daphnia magna was reduced even at approximately half the recommended amount of sodium thiosulfate. Formation of metal-thiosulfate complexes that are less bioavailable may explain the apparent reduction of metal toxicity. In contrast, for samples spiked with Zn(II), dechlorination with sodium thiosulfate increased toxicity. The use of sodium thiosulfate for dechlorination should be cautioned when the sample under the bioassay is potentially contaminated with metals.
美国环境保护局建议在进行毒性测试之前，使用硫代硫酸钠对含有残留氯的废水样本进行脱氯处理。然而，对于被残留氯和金属（如镉（II）、铜（II）和镍（II））污染的样本，即使使用的硫代硫酸钠量约为推荐量的一半，用大型溞测量的金属毒性也会降低。形成生物可利用性较低的金属硫代硫酸盐络合物可能解释了金属毒性的明显降低。相比之下，对于添加了锌（II）的样本，用硫代硫酸钠脱氯会增加毒性。当生物测定中的样本可能被金属污染时，应谨慎使用硫代硫酸钠进行脱氯处理。
