通过在消毒之前对实际水样中的天然产物成分进行非目标分析,香豆素被检测为最丰富的化合物之一。更重要的是,腐殖酸的预氯化产生3-羟基香豆素和单羟基单甲基取代的香豆素,总收率≤10.1%,这表明原水中的腐殖质是香豆素的重要来源。7-羟基香豆素,6-羟基-4-甲基香豆素,6,7-二羟基香豆素,和7-甲氧基-4-甲基香豆素在原水中通过高效液相色谱-串联高分辨率质谱鉴定,因为只有一些香豆素标准是市售的。他们的氯化产生了单氯化和多氯香豆素,并且它们的结构被合成标准所证实。这些产品可以在不同剂量的氯和pH水平下形成,一些浓度为600ng/L的自来水可以在自来水中稳定几天。3,6,8-三氯-7-羟基香豆素,3-氯-7-甲氧基-4-甲基香豆素,和3,6-二氯-7-甲氧基-4-甲基香豆素首次在成品水中鉴定,浓度为0.0670、78.1和14.7ng/L,分别,但不是在水源水中,这表明它们是在消毒过程中形成的新DBPs。在TIC-Tox分析中,3-氯-7-甲氧基-4-甲基香豆素在CHO-K1细胞中的细胞毒性与2,6-二溴-1,4-苯醌和2,6-二氯-1,4-苯醌相当,这表明有必要进一步调查它们在饮用水系统中的发生和控制。
Coumarin was detected as one of the most abundant compounds by nontargeted analysis of natural product components in actual water samples prior to disinfection. More importantly, prechlorination of humic acid generated 3-hydroxycoumarin and monohydroxy-monomethyl-substituted coumarin with a total yield of ≤10.1%, which suggested the humic substance in raw water is an important source of coumarins. 7-Hydroxycoumarin, 6-hydroxy-4-methylcoumarin, 6,7-dihydroxycoumarin, and 7-methoxy-4-methylcoumarin were identified in raw water by high-performance liquid chromatography-tandem high-resolution mass spectrometry because only some coumarin standards were commercially available. Their chlorination generated monochlorinated and polychlorinated coumarins, and their structures were confirmed by the synthesized standards. These products could form at various dosages of chlorine and pH levels, and some with a concentration of 600 ng/L can be stable in tap water for days. 3,6,8-Trichloro-7-hydroxycoumarin, 3-chloro-7-methoxy-4-methylcoumarin, and 3,6-dichloro-7-methoxy-4-methylcoumarin were first identified in finished water with concentrations of 0.0670, 78.1, and 14.7 ng/L, respectively, but not in source water, suggesting that they are new DBPs formed during disinfection. The cytotoxicity of 3-chloro-7-methoxy-4-methylcoumarin in CHO-K1 cells was comparable to those of 2,6-dibromo-1,4-benzoquinone and 2,6-dichloro-1,4-benzoquinone in TIC-Tox analyses, suggesting that further investigation of their occurrence and control in drinking water systems is warranted.