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Liu Y, Mekic M, Carena L, Vione D, Gligorovski S, Zhang G, Jin B. Tracking photodegradation products and bond-cleavage reaction pathways of triclosan using ultra-high resolution mass spectrometry and stable carbon isotope analysis. Environ Pollut 2020; 264:114673. [PMID: 32388298 DOI: 10.1016/j.envpol.2020.114673] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 03/12/2020] [Accepted: 04/24/2020] [Indexed: 06/11/2023]
Abstract
Triclosan (TCS) is an antimicrobial compound ubiquitously found in surface waters throughout the world. Although several studies have focused on the photochemical degradation of TCS, there is still limited knowledge about its environmental fate. In this study, we got molecular-level insights into the photochemical degradation of TCS. Significant stable carbon isotope fractionation was observed during photodegradation; different bond-cleavage reaction pathways under different photolytic conditions were characterized, using compound specific isotope analysis (CSIA). Photochemical modeling of TCS photodegradation showed that direct photolysis would be the main transformation pathway if pH > 7, even in presence of dissolved organic matter. Moreover, by use of ultrahigh resolution mass spectrometry, FT-ICR-MS, a broad and complex spectrum of organic by-products (some of which potentially toxic, as assessed by a quantitative structure-activity relationship approach) were identified. A detailed reaction mechanism was developed on the basis of the detected compounds. A possible sequence of steps leading to some of the detected product compounds in aqueous solution is suggested.
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Affiliation(s)
- Yi Liu
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China; University of Chinese Academy of Sciences, Beijing, 10069, China
| | - Majda Mekic
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China; University of Chinese Academy of Sciences, Beijing, 10069, China
| | - Luca Carena
- Department of Chemistry, University of Torino, Via Pietro Giuria 5, 10125, Torino, Italy
| | - Davide Vione
- Department of Chemistry, University of Torino, Via Pietro Giuria 5, 10125, Torino, Italy
| | - Sasho Gligorovski
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China
| | - Gan Zhang
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China
| | - Biao Jin
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China.
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