Department of Analytical Chemistry, Campus of Rabanales, University of Córdoba, E-14071 Córdoba, Spain.
Department of Analytical Chemistry, Campus of Rabanales, University of Córdoba, E-14071 Córdoba, Spain.
J Chromatogr A. 2014 May 2;1340:15-23. doi: 10.1016/j.chroma.2014.03.019. Epub 2014 Mar 13.
This paper describes the first micro liquid-liquid extraction (MLLE) gas chromatography-mass spectrometry (GC-MS) method for the speciation of emerging iodinated acetic acids, along with conventional chlorinated and brominated acids in water. The haloacetic acids (HAAs) were derivatised using 3 reagents for their methylation, both in aqueous and organic media. The acidic methanol derivatisation in aqueous medium provided the best efficiency, requiring minimal sample manipulation. The derivatisation yield was improved through the use of microwave energy that drastically reduced reaction time (2 min). The HAA methyl esters were finally extracted using 250 μL of methyl tert-butyl ether. This MLLE combined with the use of a large-volume sample injection coupled to a programmed temperature vaporiser-GC-MS improved the sensitivity of the method and minimised the generation of hazardous residues in accordance with the principles of "Green Chemistry". Detection and quantification limits (excepting tribromoacetic acid) within the range of 0.01-0.15 μg/L and 0.03-0.5 μg/L, respectively, were obtained and the relative standard deviation was lower than 10%. The eco-friendly method was applied to the speciation of the 13 HAAs in treated (chlorinated and chloraminated water) and untreated water. Up to 8 HAAs were found at detectable levels in treated water. The highly toxic monoiodoacetic acid was detected in almost all the chloraminated water.
本文描述了首个用于水中新兴碘代乙酸形态分析的微液-液萃取（MLLE）-气相色谱-质谱（GC-MS）方法，同时也可分析常规的氯代和溴代酸。卤代乙酸（HAAs）通过 3 种试剂进行甲基化衍生，包括在水相和有机相。在水相中进行酸性甲醇衍生反应效率最佳，所需样品处理最少。通过使用微波能量，反应时间大大缩短至 2 分钟，从而提高了衍生效率。最后使用 250 μL 叔丁基甲醚提取 HAA 甲酯。这种 MLLE 结合使用大体积进样和程序升温汽化器-GC-MS，提高了方法的灵敏度，并按照“绿色化学”的原则最大限度地减少了危险残留物的生成。检测和定量限（三溴乙酸除外）分别在 0.01-0.15 μg/L 和 0.03-0.5 μg/L 范围内，相对标准偏差低于 10%。该环保方法应用于处理（氯化和氯胺化水）和未处理水中 13 种 HAAs 的形态分析。在处理水中发现了 8 种可检测水平的 HAAs。几乎所有的氯胺化水中都检测到了高毒性的一碘乙酸。
