Bergström Staffan, Barri Thaer, Norberg Jan, Jönsson Jan Ake, Mathiasson Lennart
Department of Analytical Chemistry, Lund University, P.O. Box 124, S-221 00 Lund, Sweden.
Anal Chim Acta. 2007 Jul 2;594(2):240-7. doi: 10.1016/j.aca.2007.05.015. Epub 2007 May 21.
The use of the extracting syringe (ESy), a fully automated membrane-based extraction technique, for analysis of phthalate esters in complex aqueous samples has been investigated. The ESy, working as an autosampler that combines the extraction process and injection into the gas chromatograph (GC) in one single step, is placed on top of the GC equipped with a flame ionisation detector. The aqueous samples are loaded in a tray and automatically extracted by employing microporous membrane liquid-liquid extraction principle. After the extraction, the extract is directly injected into the GC's programmable temperature vaporisation injector. Six different phthalate esters were used as model compounds. Four extraction solvents were tested and the addition of sample organic modifier was examined. Toluene was the optimal solvent to use for extraction. Due to the large variation in polarity of phthalate esters, 50% methanol as organic modifier had to be added to the samples so as to extract the most nonpolar phthalate esters; di-2-ethylhexylphthalate and di-n-octylphthalate, whereas the other four relatively polar phthalate esters were extracted from unmodified samples. No significant difference between extraction of river water, leachate water from a landfill and reagent water was noted, except for minor deviations. The extraction time was 20 min for extraction of a 1-mL sample, resulting in a good linearity for all aqueous media investigated, good enrichment factors (54-110 folds) and low LOD values (0.2-10 ng mL(-1)) and relative standard deviation (%R.S.D.; 0.9-3.7%).
研究了使用萃取注射器（ESy）这种基于膜的全自动萃取技术，对复杂水样中的邻苯二甲酸酯进行分析。ESy作为一种自动进样器，将萃取过程和进样到气相色谱仪（GC）中合并为一个步骤，放置在配备火焰离子化检测器的GC顶部。水样加载到托盘中，并采用微孔膜液 - 液萃取原理自动萃取。萃取后，萃取物直接注入GC的程序升温汽化进样器。使用六种不同的邻苯二甲酸酯作为模型化合物。测试了四种萃取溶剂，并研究了样品有机改性剂的添加情况。甲苯是用于萃取的最佳溶剂。由于邻苯二甲酸酯的极性差异很大，必须向样品中添加50%甲醇作为有机改性剂，以萃取极性最小的邻苯二甲酸酯；邻苯二甲酸二（2 - 乙基己基）酯和邻苯二甲酸二正辛酯，而其他四种相对极性的邻苯二甲酸酯则从未改性的样品中萃取。除了微小偏差外，未发现河水、垃圾渗滤液和试剂水的萃取之间存在显著差异。萃取1 mL样品的萃取时间为20分钟，在所研究的所有水性介质中均具有良好的线性、良好的富集因子（54 - 110倍）和低检测限（0.2 - 10 ng mL⁻¹）以及相对标准偏差（%R.S.D.；0.9 - 3.7%）。
