Environmental Engineering Program, Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China.
Environmental Engineering Program, Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China.
J Environ Sci (China). 2017 Aug;58:83-92. doi: 10.1016/j.jes.2017.04.026. Epub 2017 May 5.
Chlorine dioxide (ClO) is a widely used alternative disinfectant due to its high biocidal efficiency and low-level formation of trihalomethanes and haloacetic acids. A major portion of total organic halogen (TOX), a collective parameter for all halogenated DBPs, formed in ClO-treated drinking water is still unknown. A commonly used pretreatment method for analyzing halogenated DBPs in drinking water is one-time liquid-liquid extraction (LLE), which may lead to a substantial loss of DBPs prior to analysis. In this study, characterization and identification of polar halogenated DBPs in a ClO-treated drinking water sample were conducted by pretreating the sample with multiple extractions. Compared to one-time LLE, the combined four-time LLEs improved the recovery of TOX by 2.3 times. The developmental toxicity of the drinking water sample pretreated with the combined four-time LLEs was 1.67 times higher than that pretreated with one-time LLE. With the aid of ultra-performance liquid chromatography/electrospray ionization-triple quadrupole mass spectrometry, a new group of polar halogenated DBPs, trihalomethanols, were detected in the drinking water sample pretreated with multiple extractions; two of them, trichloromethanol and bromodichloromethanol, were identified with synthesized standard compounds. Moreover, these trihalomethanols were found to be the transformation products of trihalomethanes formed during ClO disinfection. The results indicate that multiple LLEs can significantly improve extraction efficiencies of polar halogenated DBPs and is a better pretreatment method for characterizing and identifying new polar halogenated DBPs in drinking water.
二氧化氯 (ClO) 因其高效的杀菌能力和低水平生成三卤甲烷和卤乙酸而被广泛用作替代消毒剂。在 ClO 处理的饮用水中，总有机卤素 (TOX) 的很大一部分，即所有卤代 DBPs 的综合参数，其形成量仍不清楚。分析饮用水中卤代 DBPs 的常用预处理方法是一次性液 - 液萃取 (LLE)，这可能会导致在分析之前大量 DBPs 的损失。在这项研究中，通过多次萃取对 ClO 处理的饮用水样品中的极性卤代 DBPs 进行了特征描述和鉴定。与一次性 LLE 相比，四次组合 LLE 提高了 TOX 的回收率 2.3 倍。用四次组合 LLE 预处理的饮用水样品的发育毒性比用一次性 LLE 预处理的样品高 1.67 倍。借助超高效液相色谱/电喷雾电离-三重四极杆质谱，在经过多次萃取预处理的饮用水样品中检测到了一组新的极性卤代 DBPs——三卤甲醇；其中两种，三氯甲醇和二溴氯甲醇，用合成的标准化合物进行了鉴定。此外，这些三卤甲醇被发现是 ClO 消毒过程中形成的三卤甲烷的转化产物。结果表明，多次 LLE 可以显著提高极性卤代 DBPs 的萃取效率，是一种更好的预处理方法，用于在饮用水中鉴定和识别新的极性卤代 DBPs。
