UFZ-Helmholtz Centre for Environmental Research, Department Monitoring and Exploration Technologies, Permoserstrasse 15, D-04318 Leipzig, Germany.
Chemosphere. 2010 Jun;80(4):396-403. doi: 10.1016/j.chemosphere.2010.04.024. Epub 2010 May 4.
In order to investigate the fate of volatile pollutants such as methyl tert-butyl ether (MTBE) and benzene during the treatment of contaminated water using constructed wetlands, appropriate analytical methods for the analysis of wetland marsh plants, in our case common reed (Phragmites australis), are required. Different sampling procedures and different headspace (HS) based sample preparation techniques were examined to select and establish the most suited procedure for determining the target analytes in plant material. Static HS, dynamic HS and HS solid phase microextraction (SPME) in combination with GC-MS were optimized and evaluated regarding the extraction yields and their capability for quantitative analysis. Only dynamic HS analysis at 80 degrees C for 45min with trapping the analytes on Tenax TA/Chromosorb-106 desorption tubes and the subsequent thermodesorption GC-MS permits the quantitative analysis of MTBE and benzene in reed in a concentration range from 4ng up to 4mug per sample weight (approximately 1g). Static HS and HS SPME analyses were found to be less reliable due to the lack of suitable reference materials. Therefore, these methods do not permit the accurate quantification of pollutant content. Additionally, the HS SPME method is characterized by a restricted linear range of calibration curves. The optimized dynamic HS method was successfully applied for the quantitative analysis of MTBE and benzene within the plants. Their distribution within the plant depending on its height shows a different behavior due to differences in degradability of both substances. While a strong decrease of the concentration of benzene with increasing height of plant was found, the decrease of the concentration of MTBE was not as obvious as observed for benzene. Furthermore, the assessment of plant uptake during phytoremediation was demonstrated by analyzing complete plants for the constructed wetlands investigated.
为了研究挥发性污染物（如甲基叔丁基醚（MTBE）和苯）在使用人工湿地处理受污染水时的命运，需要适当的分析方法来分析湿地沼泽植物，在我们的案例中是普通芦苇（Phragmites australis）。研究了不同的采样程序和不同的顶空（HS）基础样品制备技术，以选择和建立最适合于确定植物材料中目标分析物的程序。对静态 HS、动态 HS 和 HS 固相微萃取（SPME）与 GC-MS 的结合进行了优化和评估，以考察提取产率及其进行定量分析的能力。只有在 80°C 下进行 45min 的动态 HS 分析，并用 Tenax TA/Chromosorb-106 吸附管捕集分析物，然后进行热解吸 GC-MS，才能在样品重量（约 1g）为 4ng 至 4μg 的浓度范围内定量分析芦苇中的 MTBE 和苯。由于缺乏合适的参考材料，静态 HS 和 HS SPME 分析被发现不太可靠。因此，这些方法不允许对污染物含量进行准确的定量分析。此外，HS SPME 方法的校准曲线线性范围有限。优化后的动态 HS 方法成功地应用于植物内 MTBE 和苯的定量分析。根据其高度，它们在植物内的分布表现出不同的行为，这是由于两种物质的降解性不同所致。虽然随着植物高度的增加，苯的浓度明显下降，但 MTBE 的浓度下降并不像苯那样明显。此外，通过分析人工湿地中完整的植物，证明了该方法可用于评估植物修复过程中的植物吸收。
