Toxicity of disinfection byproducts formed during the chlorination of sulfamethoxazole, norfloxacin, and 17β-estradiol in the presence of bromide

Zhang, Yuanyuan; Zhu, Yunjie; Shao, Yongfu; Rong, Chuanbing; Pan, Zihan; Deng, Jie

doi:10.1007/s11356-021-14161-5

Cited by 5 publications

(2 citation statements)

References 65 publications

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“…Aniline-like intermediates were detected that may play critical roles in HAN formation. Considering that aniline moieties are common in synthetic chemicals such as pharmaceuticals and pesticides, our findings, combined with those from other recent DBP studies, − suggest that anilines deserve more attention as potential DBP precursors. In this study, our approach to HRMS data analysis approximates that of a suspect screening, where candidate intermediates were proposed based on literature review.…”

Section: Environmental Implicationssupporting

confidence: 70%

Overlooked Contribution of the Indole Moiety to the Formation of Haloacetonitrile Disinfection Byproducts

Kralles

Werner

Dai

2023

Environ. Sci. Technol.

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Haloacetonitriles (HANs) are a group of disinfection byproducts with high toxicity and frequent occurrence. Past studies have focused on the free amine groups, especially those in amino acids, as HAN precursors. This study reports, for the first time, that the indole moiety such as that in the tryptophan side chain is also a potent precursor for the most common HANs dichloroacetonitrile, bromochloroacetonitrile, and dibromoacetonitrile. 3-Indolepropionic acid, differing from tryptophan only in the absence of the free amine group, formed HANs at levels 57–76% of those by tryptophan at a halogen/nitrogen molar ratio of 10. Experiments with tryptophan-(amino-15N) showed that the indole contributed to 28–51% of the HANs formed by tryptophan. At low oxidant excess (e.g., halogen/precursor = 5), 3-indolepropionic acid even formed more HANs than Trp by 3.5-, 2.5-, and 1.8-fold during free chlorination, free bromination, and chlorination in the presence of bromide (0.6 mg/L), respectively. Indole’s HAN formation pathway was investigated by exploring the chlorination/bromination products of 3-indolepropionic acid using liquid chromatography–orbitrap high-resolution mass spectrometry. A total of 22 intermediates were detected, including pyrrole ring-opening products with an N-formyl group, 2-substituted anilines with different hydroxyl/halogen substitutions, and an intermediate with a postulated non-aromatic ring structure.

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Section: Environmental Implicationssupporting

confidence: 70%

Overlooked Contribution of the Indole Moiety to the Formation of Haloacetonitrile Disinfection Byproducts

Kralles

Werner

Dai

2023

Environ. Sci. Technol.

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“…Previous studies have reported effective and reliable QSAR models for toxicity estimation of pesticides [ 18 , 23 ], 1,2,4-triazoles [ 24 ], pharmaceuticals and persistent organic pollutants [ 18 ], halogen derivatives, ethers and tertiary amines [ 25 ]. The molecular descriptors that describe the electrical, hydrophobicity, and thermodynamic structural characteristics, such as the energy of the highest unoccupied molecular orbital (E HOMO ), octanol-water partition coefficient (logK ow ), and overall or summation solute hydrogen bond basicity (MLFER_BO), were often found to be strongly correlated with the toxicity of chemicals [ [26] , [27] , [28] , [29] , [30] ]. However, little attention was paid to systematically investigate the quantitative relationship between the molecular structure and the biotoxicity and developed QSAR models for biotoxicity estimation of PHDs.…”

Section: Introductionmentioning

confidence: 99%