Department of Analytical Chemistry, Campus of Rabanales, University of Córdoba, Córdoba, Spain.
Anal Chim Acta. 2013 Jun 19;784:77-84. doi: 10.1016/j.aca.2013.04.059. Epub 2013 May 10.
Aldehydes are produced in water disinfected primarily by ozone treatment, and are generally present in treated water below the limit of detection (<5 μg L(-1)) of commonly proposed methods. Formaldehyde is the most studied along with acetaldehyde due to their mutagenic character, and because it causes chromosomal aberrations. This paper reports the first miniaturised system for the simultaneous determination of thirteen aldehydes (aliphatic and aromatic) which are selected based on their frequent or suspected presence in water, mainly as disinfection by-products (DBPs). The micro liquid-liquid extraction (MLLE) method is a miniaturisation of EPA Method 556.1 for carbonyl compounds that includes some innovations, such as performing the derivatising reaction in a strong acidic medium (pH 1.1), and the addition of magnesium sulphate to the aqueous layer as the heating agent, which allows to carry out the whole simultaneous derivatisation/microextraction process in only 1 min. Large-volume sample injection (50 μL) coupled to programmed temperature vaporiser-gas chromatography-mass spectrometry is also used to improve both sensitivity and selectivity. The MLLE method demonstrated high extraction efficiency (96%) with low limits of detection, between 0.7 and 80 ng L(-1), and good precision (RSD below 10%, n=11). The proposed method was evaluated by determining aldehydes in water. Our study demonstrated that the selection of the target aldehydes was appropriate since all were found (at average concentrations from 8.0 to 1.4 μg L(-1) for aliphatic and aromatic aldehydes, respectively) in swimming pool waters as DBPs.
醛类物质主要通过臭氧处理的方式产生于饮用水消毒过程中，通常在经过提议的常用方法检测限（<5μg/L）以下的处理水中存在。由于其致突变特性，以及会导致染色体畸变，甲醛和乙醛是研究最多的两种醛类物质。本文报告了首个用于同时测定 13 种醛类物质（脂肪族和芳香族醛类）的微型化系统，这些物质是基于其在水中的频繁或可疑存在情况选择的，主要作为消毒副产物（DBPs）。微型液液萃取（MLLE）方法是 EPA 方法 556.1 中用于羰基化合物的微型化方法，其中包含一些创新，例如在强酸介质（pH 值 1.1）中进行衍生化反应，以及在水相中添加硫酸镁作为加热剂，这使得整个同时衍生化/微型萃取过程仅需 1 分钟即可完成。大体积样品进样（50μL）与程序升温汽化器-气相色谱-质谱联用，也用于提高灵敏度和选择性。MLLE 方法表现出高萃取效率（96%），低检出限介于 0.7 和 80ng/L 之间，且精密度良好（RSD 低于 10%，n=11）。通过在游泳池水中测定醛类物质对该 MLLE 方法进行了评估。我们的研究表明，目标醛类物质的选择是合适的，因为所有这些物质（在脂肪族和芳香族醛类物质的平均浓度分别为 8.0 和 1.4μg/L 左右）都被发现作为泳池水中的 DBPs。
