Physical Chemistry Department, Faculty of Marine and Environmental Sciences, University of Cadiz, Spain.
Chemosphere. 2014 Jan;95:478-85. doi: 10.1016/j.chemosphere.2013.09.101. Epub 2013 Nov 5.
We have developed a method for the analysis of two sewage-derived contaminants: triclosan (TCS), an antibacterial agent, and methyl triclosan (MTCS), a TCS metabolite. For solid samples (4 g), extraction and cleanup were integrated into the same step using pressurized liquid extraction (PLE) with in-cell-clean-up (1g of florisil). The extraction was performed using dichloromethane at 100 °C, 1500 psi and 3 static extraction cycles of 5 min each. For water samples (100mL), stir bar sorptive extraction-liquid desorption (SBSE-LD) was used. Bars were stirred for 10h and analytes were later desorbed using acetonitrile. Finally, MTCS and a silylated derivative of TCS were determined by gas chromatography-mass spectrometry (GC-MS). Recovery experiments in water and sediments were performed and the results ranged from 67% to 78%. Limits of detection (LODs) were 5 ng L(-1) for TCS and 1 ng L(-1) for MTCS, in water samples, and 0.1 ng g(-1) for TCS and MTCS in solid samples. The method was applied then to determine the levels of these compounds in the estuary of Guadalete River (SW Spain). TCS and MTCS concentrations up to 9.6 ng g(-1) in sediments and 310 ng L(-1) in water were measured. Their distribution was strongly influenced by the presence of wastewater sources, treated and untreated, along the sampling area, where maximum concentrations were detected. Highest values were reached in the water column during low tides as the water volume in the estuary becomes lower.
三氯生（TCS），一种抗菌剂，和甲基三氯生（MTCS），TCS 的代谢物。对于固体样品（4 克），提取和净化在同一步骤中集成，使用加压液体提取（PLE）和细胞内净化（1 克佛罗里硅土）。提取在 100°C、1500 psi 和 3 个静态提取循环下进行，每个循环持续 5 分钟，使用二氯甲烷。对于水样（100mL），使用搅拌棒吸附萃取-液体解吸（SBSE-LD）。搅拌棒搅拌 10 小时，然后用乙腈解吸分析物。最后，通过气相色谱-质谱联用仪（GC-MS）测定 MTCS 和 TCS 的硅烷化衍生物。在水和沉积物中进行了回收实验，结果范围为 67%至 78%。TCS 和 MTCS 在水中的检出限（LOD）分别为 5 ng L(-1)和 1 ng L(-1)，在固体样品中的检出限分别为 0.1 ng g(-1)和 0.1 ng g(-1)。然后该方法应用于测定瓜达莱特河口（西班牙西南部）这些化合物的水平。在沉积物中检测到 TCS 和 MTCS 的浓度高达 9.6 ng g(-1)，在水中的浓度高达 310 ng L(-1)。它们的分布受到污水来源（处理和未处理）的强烈影响，在采样区域中存在最大浓度。在低潮时，由于河口中的水体积减少，最高浓度出现在水柱中。
