Chemistry Program, Department of Science, Graduate School of Science and Engineering, Kagoshima University, 1-21-35 Korimoto, Kagoshima, 890-0065, Japan.
Chemistry Program, Department of Science, Graduate School of Science and Engineering, Kagoshima University, 1-21-35 Korimoto, Kagoshima, 890-0065, Japan.
Chemosphere. 2023 Dec;344:140308. doi: 10.1016/j.chemosphere.2023.140308. Epub 2023 Sep 26.
Neutral low-molecular-weight organics such as methyl nitrate that can readily pass through reverse osmosis (RO) membranes employed in potable water reuse facilities attract interest owing to public health considerations. In this study, a novel determination method based on high-performance liquid chromatography, online photochemical conversion to peroxynitrite, and luminol chemiluminescence detection was developed for methyl nitrate measurement in treated water. The maximum photochemical conversion efficiency of methyl nitrate to peroxynitrite was found to be 6.5% using a 222-nm excimer lamp. The calibration curve for the developed method was linear between 1.0 × 10 and 1.0 × 10 M, and the limit of detection was 0.3 nM (0.03 μg/L) given an injection volume of 200 μL. The methyl nitrate concentrations in RO permeate from reclaimed wastewater and product water after subsequent treatment by a UV/HO advanced oxidation process (AOP) were 2.2 and 22.5 nM (0.17 and 1.7 μg/L), respectively. UV irradiation of RO permeate in the laboratory using a low-pressure Hg lamp confirmed the formation of methyl nitrate in the permeate in the absence of HO and residual chloramines. This chemiluminescent detection method for methyl nitrate will promote a greater understanding of the origin and formation of this treatment byproduct in reclaimed wastewater.
中性低分子量有机物，如可轻易穿透饮用水回用设施中所使用的反渗透（RO）膜的硝酸甲酯，由于公众健康方面的考虑而受到关注。在这项研究中，开发了一种基于高效液相色谱、在线光化学转化为过氧亚硝酸根和鲁米诺化学发光检测的新方法，用于处理水中的硝酸甲酯测量。使用 222nm 准分子灯，发现硝酸甲酯向过氧亚硝酸根的最大光化学转化效率为 6.5%。所开发方法的校准曲线在 1.0×10 和 1.0×10 M 之间呈线性，在注射体积为 200 μL 的情况下，检测限为 0.3 nM（0.03 μg/L）。再生废水的 RO 渗透物以及后续 UV/HO 高级氧化工艺（AOP）处理后的产品水中的硝酸甲酯浓度分别为 2.2 和 22.5 nM（0.17 和 1.7 μg/L）。在实验室中使用低压汞灯对 RO 渗透物进行紫外线照射，证实了在没有 HO 和残余氯胺的情况下，渗透物中形成了硝酸甲酯。这种用于硝酸甲酯的化学发光检测方法将促进对再生废水中这种处理副产物的来源和形成的更深入了解。
