Engineering Research Equipment: Multidimensional Gas Chromatography System

这笔设备赠款将用于购买多维气相色谱系统，以支持德雷塞尔大学的燃烧研究活动。从类燃料碳氢化合物的氧化中分离中间体和产物的复杂分析问题需要复杂的色谱技术。提供这些能力的两种互补方法是毛细管柱和计算机控制的程控瓣膜切换，也称为多维或“心脏切割”分析。虽然毛细管柱本身提供了更高的分辨率，但它们不足以分离非常复杂的烷烃、烯烃和含氧物混合物。为了实现分离，通常需要使用多个柱，这些柱在分析期间切换到载气和从载气中移出。进一步的分离通常是通过将选定的部分气体样品保存在柱中并将该部分样品反冲洗到第二分析柱中来实现的。这项技术被称为多维气相色谱，并已成功地应用于碳氢化合物氧化研究。将要购买的系统将允许实施这些复杂的分离技术。为了能够分析永久性气体，该系统将被配置为允许使用火焰电离和热导检测器的双检测器操作。在了解全沸点燃料的氧化和点火特性之前，有必要对纯单组分燃料及其简单混合物的氧化和点火特性有基本的了解。这需要开发详细的动力学机制并使用分析技术进行验证，以评估燃烧过程中形成的反应中间体和产物。随着燃料分子量的增加，形成的这类物种的数量逐渐增加。因此，用传统的气相色谱测定所涉及的大量化合物变得极其困难和繁琐。多维气体分离技术的使用极大地方便了多组分样品的物种鉴定，从而允许对现实中较高分子量碳氢化合物的氧化化学进行基础研究。

This equipment grant will be used to purchase a multidimensional gas chromatography system to support combustion research activities at Drexel University. The complex analytical problems of separating the intermediates and products from the oxidation of fuel-like hydrocarbons require sophisticated chromatographic techniques. Two complementary methodologies to provide these capabilities are capillary columns and computer-controlled programmed valve switching, also called multi-dimensional or "heart cutting" analysis. While capillary columns by themselves provide increased resolution, they have not been sufficient to separate very complicated mixtures of alkanes, olefins, and oxygenates. To achieve separation, it is often necessary to use multiple columns which are switched into and out of the carrier gas during an analysis. Further separation is often achieved by holding selected fractions of the gas sample in a column and backflushing this partial sample into a second analytical column. This technique is called multidimensional gas chromatography and has been successfully applied to hydrocarbon oxidation studies. The system to be purchased will permit implementation of these sophisticated separation techniques. To allow analysis of permanent gases, the system will be configured to allow dual detector operation using both flame ionization and thermal conductivity detectors. It is necessary to have a basic understanding of the oxidation and ignition characteristics of pure single component fuels and simple mixtures of these fuels before understanding of the oxidation and ignition characteristics of full-boiling range fuels can be developed. This requires development of detailed kinetic mechanisms and verification using analysis techniques to assess the reaction intermediates and products formed during the combustion process. The number of such species formed progressively increases with increasing molecular weight of the fuel. Thus, determination of the large number of compounds involved using conventional gas chromatography becomes extremely difficult and tedious. Use of multidimensional gas separation techniques greatly facilitates species identification for multicomponent samples and thus allows for basic research into the oxidation chemistry of realistic hydrocarbons of higher molecular weight.