Curtin Water Quality Research Centre, Department of Chemistry, Curtin University, GPO Box U1987, Perth, Western Australia 6845, Australia.
J Chromatogr A. 2012 May 18;1238:15-21. doi: 10.1016/j.chroma.2012.03.020. Epub 2012 Mar 23.
Trihalomethanes are predominantly formed during disinfection of water via reactions of the oxidant with natural organic matter. Even though chlorinated and brominated trihalomethanes are the most widespread organic contaminants in drinking water, when iodide is present in raw water iodinated trihalomethanes can also be formed. The formation of iodinated trihalomethanes can lead to taste and odor problems and is a potential health concern since they have been reported to be more toxic than their brominated or chlorinated analogs. Currently, there is no published standard analytical method for I-THMs in water. The analysis of 10 trihalomethanes in water samples in a single run is challenging because the iodinated trihalomethanes are found at very low concentrations (ng/L range), while the regulated chlorinated and brominated trihalomethanes are present at much higher concentrations (above μg/L). An automated headspace solid-phase microextraction technique, with a programmed temperature vaporizer inlet coupled with gas chromatography-mass spectrometry, was developed for routine analysis of 10 trihalomethanes i.e. bromo-, chloro- and iodo-trihalomethanes in water samples. The carboxen/polydimethylsiloxane/divinylbenzene fiber was found to be the most suitable. The optimization, linearity range, accuracy and precision of the method are discussed. The limits of detection range from 1 ng/L to 20 ng/L for iodoform and chloroform, respectively. Matrix effects in treated groundwater, surfacewater, seawater, and secondary wastewater were investigated and it was shown that the method is suitable for the analysis of trace levels of iodinated trihalomethanes in a wide range of waters. The method developed in the present study has the advantage of being rapid, simple and sensitive. A survey conducted throughout various process stages in an advanced water recycling plant showed the presence of iodinated trihalomethanes at ng/L levels.
三卤甲烷主要是在通过氧化剂与天然有机物反应对水进行消毒时形成的。即使氯化和溴化三卤甲烷是饮用水中最广泛存在的有机污染物，但当原水中存在碘化物时，也可以形成碘化三卤甲烷。碘化三卤甲烷的形成会导致味道和气味问题，并且是一个潜在的健康问题，因为据报道它们比其溴化或氯化类似物更具毒性。目前，水中 I-THMs 尚无公布的标准分析方法。由于碘代三卤甲烷的浓度非常低（ng/L 范围），而受管制的氯化和溴化三卤甲烷的浓度则高得多（μg/L 以上），因此在一次运行中分析水样中的 10 种三卤甲烷具有挑战性。开发了一种自动化顶空固相微萃取技术，带有程序升温汽化器入口，与气相色谱-质谱联用，用于常规分析水样中的 10 种三卤甲烷，即溴代、氯代和碘代三卤甲烷。发现羧基/聚二甲基硅氧烷/二乙烯基苯纤维最适合。讨论了方法的优化、线性范围、准确性和精密度。检测限范围分别为碘仿和氯仿的 1ng/L 至 20ng/L。研究了经处理的地下水、地表水、海水和二级废水的基质效应，表明该方法适用于分析各种水中痕量的碘化三卤甲烷。本研究中开发的方法具有快速、简单和灵敏的优点。在一个先进的水回收厂的各个工艺阶段进行的调查显示，在 ng/L 水平存在碘化三卤甲烷。
