Laboratory of Analytical Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimioupolis Zografou, 15771, Athens, Greece.
Laboratory of Analytical Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimioupolis Zografou, 15771, Athens, Greece.
J Hazard Mater. 2019 Mar 5;365:804-812. doi: 10.1016/j.jhazmat.2018.11.046. Epub 2018 Nov 17.
In this study, the removal of niflumic acid (NA) and the identification of its transformation products (TPs) during ozonation was investigated. The influence of initial ozone concentration and pH value on NA's removal was tested, while suspect and non-target screening approaches were followed for the identification of ozonation TPs. The structure elucidation was based on accurate mass and isotopic pattern criteria and interpretation of the acquired MS/MS spectra. Moreover, an in-house retention time prediction model was used as a supporting tool for their identification. Results indicated the highly reactivity of NA with the molecular ozone, since the reaction was extremely fast and was completed within the first minute of the reaction. A total of thirteen TPs of NA were identified, and their proposed structures show that the oxidation occurred in the heterocyclic ring of the molecule, while the aniline-like part remained intact by ozone attack due to the presence of the three fluoride atoms, which act as electron withdrawing groups. Ozonation experiments were conducted also using the most abundant TP of NA as parent compound. Three second generation TPs of NA were detected and possible structures were proposed.
在这项研究中，考察了臭氧氧化过程中尼氟酸（NA）的去除及其转化产物（TPs）的鉴定。测试了初始臭氧浓度和 pH 值对 NA 去除的影响，同时采用可疑和非靶向筛选方法鉴定臭氧 TPs。结构解析基于精确质量和同位素模式标准，并对获得的 MS/MS 谱进行解释。此外，还使用内部保留时间预测模型作为鉴定的辅助工具。结果表明，NA 与分子臭氧的反应非常迅速，因为反应在反应的最初一分钟内就已完成。共鉴定出 13 种 NA 的 TPs，其提出的结构表明，氧化发生在分子的杂环中，而由于存在三个氟原子，苯胺样部分在臭氧攻击下保持完整，因为氟原子作为吸电子基团。还使用 NA 的最丰富的 TP 作为母体化合物进行了臭氧氧化实验。检测到三种第二代 NA 的 TPs，并提出了可能的结构。
