MRI: Development of a Field-deployable Low-pressure Gas Chromatograph with Chemical Ionization Detection

在大气中，以气体和气溶胶相发现的许多氧化程度较高的化合物，由于其高反应性和倾向于分解或与其他化学物质和表面结合，对化学家来说，识别和测量是一个挑战。它们可能具有相同的分子质量和分子式。加州理工学院大气化学家将采用加州理工学院开发的化学电离聚类方法，采用具有高灵敏度检测方案的气相色谱质谱计（GC/MS）检测多功能有机化合物。该项目建立在一个现有的测试平台上，研究人员已经证明了不稳定（易碎）有机过氧化物、羟基硝酸盐和羟基酮通过标准色谱柱的高透射率，该色谱柱在质谱测量之前将它们分离。该方法的开发涉及科学家、仪器制造商、机械师和软件工程师团队的合作，以创建一个新的仪器。在学术机构中保持建立这种工具的能力是很重要的。该项目涉及仪器科学研究生的培训，为培养下一代分析化学家提供了一个平台。

Many of the more oxidized compounds found in the atmosphere, in gas and aerosol phases, represent a challenge for chemists to identify and measure due to their high reactivity, and propensity to breakdown or combine with other chemical species and surfaces. They may have the same molecular mass and formula. CalTech atmospheric chemists will adapt a gas chromatography mass spectrometer (GC/MS) with a highly sensitive detection scheme for multifunctional organic compounds using a chemical-ionization clustering method developed at Caltech. The project builds off an existing testbed where researchers have demonstrated high transmission of otherwise labile (fragile) organic peroxides, hydroxynitrates, and hydroxyl-ketones through a standard chromatographic column, which separates them prior to their measurement by a mass spec. The development of this methodology involves collaboration of a team of scientists, instrument builders, machinists, and software engineers to create a new instrument. It is important to maintain the capability to build such instruments in an academic institution. This project involves the training of a graduate student in instrumentation science, providing a platform for training the next generation of analytical chemists.