Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta Edmonton, AB, T6G 2G3, Canada.
Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta Edmonton, AB, T6G 2G3, Canada; Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Guangzhou Key Laboratory Environmental Catalysis and Pollution Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China.
Water Res. 2021 Jan 1;188:116542. doi: 10.1016/j.watres.2020.116542. Epub 2020 Oct 20.
Comprehensive identification of byproducts including intermediate transformation products (TPs) of micropollutants in source water is challenging and paramount for assessment of drinking water quality and treatment technologies. Here, we have developed a nontargeted analysis strategy coupled with computational toxicity assessment to identify indistinguishable TPs including isomers with large differences in toxicity. The new strategy was applied to study the UV treatment of water containing micropollutant 2-mercaptobenzothiazole (2-MBT), and it enabled successful identification of a total of 22 organic TPs. Particularly, the structures of nine new TPs were identified for the first time; in addition, three isomers (P2, P3, and P4) were distinguished from the toxic contaminant 2-hydroxybenzothiazole (2-OH-BT). Computational assessments indicate that estrogenic activity of the three isomers (P2-P4) is higher than that of 2-OH-BT. Mass balance study shows that the 22 organic products accounted for 70% of the 2-MBT degraded, while 30% may degrade to inorganic products. Most TPs are resistant to UV photolysis. Computational toxicity assessment predicted the TPs to increase inhibition of human thyroperoxidase activity although they have lower aquatic toxicity compared to original 2-MBT. This study emphasizes the importance of monitoring the 2-MBT photodegradation products and the overall toxicity of finished water whose production included a UV light-based treatment process.
全面识别水源中包括中间转化产物（TPs）在内的微量污染物副产物对于评估饮用水水质和处理技术至关重要。在这里，我们开发了一种非靶向分析策略，并结合计算毒性评估，以识别包括毒性差异较大的同分异构体在内的难以区分的 TPs。该新策略用于研究含有微量污染物 2-巯基苯并噻唑（2-MBT）的水的 UV 处理，成功鉴定出了总共 22 种有机 TPs。特别是，首次鉴定出了 9 种新 TPs 的结构；此外，还从有毒污染物 2-羟基苯并噻唑（2-OH-BT）中区分出了 3 种同分异构体（P2、P3 和 P4）。计算评估表明，这 3 种同分异构体（P2-P4）的雌激素活性高于 2-OH-BT。质量平衡研究表明，22 种有机产物占 2-MBT 降解的 70%，而 30%可能降解为无机产物。大多数 TPs 对 UV 光解具有抗性。计算毒性评估预测 TPs 会增加对人甲状腺过氧化物酶活性的抑制，尽管它们的水生毒性比原始 2-MBT 低。本研究强调了监测 2-MBT 光降解产物和包括基于紫外线处理工艺在内的出水总体毒性的重要性。
