Department of Analytical Chemistry, University of Granada, Granada, Spain.
Environ Toxicol Chem. 2011 Apr;30(4):813-8. doi: 10.1002/etc.447. Epub 2011 Feb 4.
We propose a study of the matrix effect in the determination of linear alkylbenzene sulfonates (LAS) in sewage sludge samples. First, a rapid, selective and sensitive method is proposed. The method involves two stages: the extraction of the compound from the samples and analysis by liquid chromatography with fluorescence detection (LC-FLD). Three different techniques of extraction (microwave-assisted extraction, Soxhlet, and ultrasounds) were compared, and microwave-assisted extraction was selected as the best suited for our purpose. Microwave-assisted extraction allows reducing the extraction time (25 min compared with 12 h for conventional Soxhlet extraction) and solvent waste (25 ml of methanol compared with 200 ml for Soxhlet or more than 50 ml for the ultrasonic procedure). Absence of matrix effect was evaluated with two standards (2ØC(8:0) and 2ØC(16:0) ) that are not commercial; therefore, neither of them was detected in sewage sludge samples and they showed similar environmental behavior (adsorption and precipitation) to LAS (C(11:0) -C(13.0) ), which allow us to evaluate the matrix effect. Validation was carried out by a recovery assay, and the method was applied to samples from different sources; therefore, they had different compositions.
我们提出了一种研究污水污泥样品中线性烷基苯磺酸盐（LAS）基质效应的方法。首先，提出了一种快速、选择性和灵敏的方法。该方法包括两个阶段：从样品中提取化合物和通过液相色谱-荧光检测（LC-FLD）进行分析。比较了三种不同的提取技术（微波辅助提取、索氏提取和超声波提取），选择微波辅助提取作为最适合我们目的的方法。微波辅助提取允许减少提取时间（与传统的索氏提取相比，25 分钟与 12 小时相比）和溶剂浪费（与索氏提取相比，25 毫升甲醇与 200 毫升相比，或超声波程序超过 50 毫升）。通过两种标准（2ØC(8:0)和 2ØC(16:0)）评估不存在基质效应，这两种标准均不是商业标准；因此，它们均未在污水污泥样品中检测到，并且它们表现出与 LAS（C(11:0) -C(13.0)）相似的环境行为（吸附和沉淀），这允许我们评估基质效应。通过回收率测定进行了验证，该方法适用于来自不同来源的样品；因此，它们具有不同的成分。
