<i>In situ</i> acetylation dispersive liquid–liquid microextraction followed by gas chromatography–mass spectrometry for the simultaneous determination of musks, triclosan and methyl-triclosan in wastewaters

A rapid and environmental-friendly analytical method for the simultaneous analysis of different personal care products (PCPs) namely synthetic musks (nitro-, polycyclic and macrocyclic musks) and the disinfectant triclosan (TCS) and its transformation product methyl-TCS in wastewater samples has been developed. The method combines dispersive liquid–liquid microextraction with <i>in situ</i> aqueous derivatisation using acetic anhydride (Ac2O) prior to gas chromatography–mass spectrometry analysis. Several parameters affecting both extraction and derivatisation efficiency (e.g. type and volume of extractor and dispersive solvents, volume of derivatising reagent, etc.) were optimised to achieve reliable conditions. Validation of the method for all compounds under study showed good linearity with coefficient of correlation &gt; 0.9947. Limits of quantification (LOQs) ranged between 2 and 72 ng/L for musks and 28 and 31 ng/L for TCS and methyl-TCS, respectively. Accuracy, expressed as the average recoveries, ranged between 76% and 87%, and precision, expressed in terms of intraday repeatability (%RSD), was better than 13% for all analytes. The application of the method to the analysis of 24 wastewater samples enabled the detection of all the target PCPs at concentration levels up to 2.7 μg/L, being galaxolide (HHCB) and tonalide (AHTN) the more prevalent, present in 88% and 46% of the samples, respectively.本研究开发了一种快速且环境友好的分析方法，可同时测定废水样品中的多种个人护理产品（Personal Care Products, PCPs），具体包括合成麝香（硝基麝香、多环麝香与大环麝香）、消毒剂三氯生（triclosan, TCS）及其转化产物甲基三氯生（methyl-TCS）。该方法将分散液-液微萃取与气相色谱-质谱分析前的原位水溶液衍生化技术相结合，所用衍生化试剂为乙酸酐（acetic anhydride, Ac₂O）。研究对影响萃取与衍生化效率的多项参数（如萃取溶剂与分散溶剂的种类、体积，衍生化试剂体积等）进行了优化，以确立可靠的分析条件。对所研究的全部化合物的方法验证结果显示，该方法具有良好的线性相关性，相关系数均大于0.9947。各类麝香的定量限（limits of quantification, LOQs）介于2~72 ng/L之间，三氯生与甲基三氯生的定量限则分别为28~31 ng/L。以平均回收率表征的准确度介于76%~87%之间；精密度以日内重复性的相对标准偏差（relative standard deviation, %RSD）表示，所有分析物的RSD均低于13%。将该方法应用于24份废水样品的分析，成功检出了所有目标个人护理产品，其浓度最高可达2.7 μg/L；其中佳乐麝香（galaxolide, HHCB）与吐纳麝香（tonalide, AHTN）最为普遍，分别在88%和46%的样品中被检出。