Transformation of iopamidol during chlorination.
Transformation of iopamidol during chlorination.
复制标题
氯化过程中碘帕醇的转化
DOI：
10.1021/es503609s
复制
发表时间：
2014
影响因子：
11.4
通讯作者：
Thomas A. Ternes
中科院分区：
文献类型：
--
作者：
Friedrich M. Wendel;Christian Lütke Eversloh;Edward J. Machek;Stephen E. Duirk;Michael J. Plewa;Susan D. Richardson;Thomas A. Ternes
在次氯酸钠、一氯胺和二氧化氯存在下，在 pH 值范围为 6.5 至 8.5 的纯净水中检查了碘化 X 射线造影剂 (ICM) 碘帕醇、碘普罗胺、碘海醇、碘美丙醇和泛影酸盐的转化。在氯水存在下，仅碘帕醇发生转化。无论使用何种氧化剂，所有其他 ICM 均未表现出显着的反应性。碘帕醇的氯化发生二级反应，在 pH 8.5 时观察到的速率常数高达 0.87 M–1s–1(±0.021 M–1s–1)。次氯酸根阴离子被鉴定为活性氯物种。碘帕醇转化过程中释放出碘，主要被氧化成碘酸盐。只有一小部分（24 小时后小于 2%）转化为已知的低分子量有机碘化消毒副产物 (DBP)。一些碘仍然存在于高分子量 DBP 中。通过 MS 断裂和 NMR 阐明了这些 DBP 的化学结构。观察到侧链断裂以及碘与氯的交换。提出了碘帕醇降解的总体转化途径。 CHO 细胞慢性细胞毒性测试表明碘帕醇的氯化会产生高分子量 DBP 的有毒混合物 (LC50332 ng/μL)。
The transformation of the iodinated X-ray contrast media (ICM) iopamidol, iopromide, iohexol, iomeprol, and diatrizoate was examined in purified water over the pH range from 6.5 to 8.5 in the presence of sodium hypochlorite, monochloramine, and chlorine dioxide. In the presence of aqueous chlorine, only iopamidol was transformed. All other ICM did not show significant reactivity, regardless of the oxidant used. Chlorination of iopamidol followed a second order reaction, with an observed rate constant of up to 0.87 M–1s–1(±0.021 M–1s–1) at pH 8.5. The hypochlorite anion was identified to be the reactive chlorine species. Iodine was released during the transformation of iopamidol, and was mainly oxidized to iodate. Only a small percentage (less than 2% after 24 h) was transformed to known organic iodinated disinfection byproducts (DBPs) of low molecular weight. Some of the iodine was still present in high-molecular weight DBPs. The chemical structures of these DBPs were elucidated via MSnfragmentation and NMR. Side chain cleavage was observed as well as the exchange of iodine by chlorine. An overall transformation pathway was proposed for the degradation of iopamidol. CHO cell chronic cytotoxicity tests indicate that chlorination of iopamidol generates a toxic mixture of high molecular weight DBPs (LC50332 ng/μL).