Department of Analytical Chemistry and Organic Chemistry, Campus Sescelades, Faculty of Chemistry, Universitat Rovira i Virgili, Marcel∙lí Domingo s/n, Tarragona 43007, Spain.
Department of Analytical Chemistry and Organic Chemistry, Campus Sescelades, Faculty of Chemistry, Universitat Rovira i Virgili, Marcel∙lí Domingo s/n, Tarragona 43007, Spain; Centre Tecnològic de la Química, Marcel·lí Domingo, s/n, Tarragona 43007, Spain.
Sci Total Environ. 2017 Dec 1;599-600:1718-1727. doi: 10.1016/j.scitotenv.2017.05.141. Epub 2017 May 19.
This study describes the humidity effect in the sampling process by adsorbent tubes followed by thermal desorption and gas chromatography-mass spectrometry (TD-GC-MS) for the determination of volatile organic compounds (VOCs) in air samples and evaluates possible solutions to this problem. Two multi-sorbent bed tubes, Tenax TA/Carbograph 1TD and Carbotrap B/Carbopack X/Carboxen 569, were tested in order to evaluate their behaviour in the presence of environmental humidity. Humidity problems were demonstrated with carbon-based tubes, while Tenax-based tubes did not display any influence. Silica gel, a molecular sieve and CaCl were tried out as materials for drying tube to remove air humidity, placed prior to the sampling tube to prevent water from entering. The pre-tubes filled with 0.5g of CaCl showed the best results with respect to their blanks, the analytes recoveries and their ability to remove ambient humidity. To avoid the possible agglomeration of CaCl during the sampling process in high relative humidity atmospheres, 0.1g of diatomaceous earth were mixed with the desiccant agent. The applicability of the CaCl pre-tube as drying agent prior to Carbotrap B/Carbopack X/Carboxen 569 tubes was tested in urban and industrial locations with samplings of air at high relative humidity. In addition, the results were compared with those obtained using Tenax TA/Carbograph 1TD tubes.
本研究描述了吸附管采样过程中的湿度效应，随后采用热解吸和气相色谱-质谱联用（TD-GC-MS）分析空气中挥发性有机化合物（VOCs），并评估了该问题的可能解决方案。为了评估其在环境湿度存在下的行为，测试了两种多吸附剂床管，Tenax TA/Carbograph 1TD 和 Carbotrap B/Carbopack X/Carboxen 569。碳基管存在湿度问题，而 Tenax 基管则没有显示出任何影响。硅胶、分子筛和 CaCl 被尝试用作干燥管的材料，以去除空气中的湿度，放置在采样管之前以防止水进入。装有 0.5g CaCl 的预填管在空白、分析物回收率及其去除环境湿度方面表现出最佳效果。为了避免在高相对湿度环境下采样过程中 CaCl 可能团聚，将 0.1g 硅藻土与干燥剂混合。在高相对湿度的城市和工业场所，使用 Carbotrap B/Carbopack X/Carboxen 569 管之前，使用 CaCl 预填管作为干燥剂的适用性进行了测试。此外，还将结果与使用 Tenax TA/Carbograph 1TD 管获得的结果进行了比较。
