Libardoni Mark, Stevens P T, Waite J Hunter, Sacks Richard
Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, United States.
J Chromatogr B Analyt Technol Biomed Life Sci. 2006 Sep 14;842(1):13-21. doi: 10.1016/j.jchromb.2006.05.008. Epub 2006 Jun 9.
A multi-bed sorption trap designed to quantitatively collect volatile organic compounds from large-volume vapor samples and inject them into a gas chromatograph is combined with a comprehensive two-dimensional gas chromatograph (GCxGC) for the analysis of organic compounds in human breath samples. The first-column effluent of the GCxGC is modulated by a single-stage, resistively-heated and air-cooled segment of 0.18-mm i.d. stainless steel column using the same stationary phase as the first column. Cooling gas is provided by a two-stage conventional refrigeration system, and thus no consumables other than carrier gas and electric power are required. The sorption trap uses four discreet beds, three containing different grades of graphitized carbon and one containing a carbon molecular sieve. The ordering of the beds in the trap tube is from the weakest to strongest adsorbent during sample collection. Breath samples are collected in gas sampling bags, and samples are passed through the trap at a flow rate of about 50 cm3/min. After sample collection, hydrogen carrier gas flow is initiated in the direction opposite to the sample collection flow, and the metal trap tube is resistively heated to inject a sample plug into the GCxGC. Performance data for the combined GCxGC/sorption-trap instrument is described, and human breath-sample chromatograms are presented.
一种多床吸附阱与全二维气相色谱仪（GCxGC）相结合，用于分析人体呼吸样本中的有机化合物。该吸附阱旨在从大量蒸汽样本中定量收集挥发性有机化合物，并将其注入气相色谱仪。GCxGC的第一柱流出物由一段内径为0.18毫米的不锈钢柱进行调制，该柱采用单级电阻加热和空气冷却，使用与第一柱相同的固定相。冷却气体由两级传统制冷系统提供，因此除了载气和电力外，无需其他耗材。吸附阱使用四个离散的床层，三个含有不同等级的石墨化碳，一个含有碳分子筛。在收集样本期间，阱管中床层的排列顺序是从最弱的吸附剂到最强的吸附剂。呼吸样本收集在气体采样袋中，样本以约50立方厘米/分钟的流速通过吸附阱。样本收集后，启动与样本收集流相反方向的氢气载气流，并对金属阱管进行电阻加热，以将样本塞注入GCxGC。描述了组合式GCxGC/吸附阱仪器的性能数据，并给出了人体呼吸样本色谱图。
