Chemical orthogonality in tandem differential mobility spectrometry at ambient pressure

在化学系化学测量和成像计划以及刺激竞争性研究实验计划办公室（EPSCoR）的支持下，州立大学新墨西哥州的加里·艾克曼教授及其团队将探索和开发使用离子迁移谱（IMS）进行化学测量的增强能力。 通过IMS的物质的化学鉴定的特异性的增加将使用由串联差分IMS分析仪中的离子变换提供的正交性来引入。 在第一迁移率分析仪中被迁移率选择并进入反应区的离子随后在进入第二迁移率分析仪之前使用分子选择性途径反应或断裂。 通过改变强电场可以增加解离性，研究将定量地揭示场强和离子结构对解离或碎裂反应的影响。 对于选定的药物和农药，调查将集中在样品衍生离子和特定试剂气体之间形成的簇的稳定性和流动性上。 将探讨和评估环境压力下空气中温度、湿度和蒸汽浓度对离子化学和化学正交性的影响，以确定下一代IMS仪器化学测量的特异性。 离子迁移谱是军事准备和商业航空安全的核心，在临床诊断和工业过程控制中产生了新的影响。 这些研究的影响应包括在环境压力下对新一代学生进行气相离子分子化学教育，并应提供新的能力，以应对工业和政府内部的具体测量挑战。

With support from the Chemical Measurement and Imaging Program in the Division of Chemistry and the Office of Experimental Program to Stimulate Competitive Research (EPSCoR), Professor Gary Eiceman at New Mexico State University and his group will explore and develop enhanced capabilities in chemical measurements using ion mobility spectrometry (IMS). Increases in specificity of a chemical identification of substances through IMS will be introduced using orthogonality provided by ion transformations in a tandem differential IMS analyzer. Ions which are mobility selected in a first mobility analyzer and passed into a reactive zone, are subsequently reacted or fragmented using molecule selective pathways before entering a second mobility analyzer. Orthogonality can be added through changes in strong electric fields and studies will disclose quantitatively the effect of field strength and ion structure on dissociation or fragmentation reactions. Investigations will focus, for selected pharmaceutical substances and pesticides, on the stability and mobility of clusters formed between sample-derived ions and specific reagent gases. The influence on ion chemistry and chemical orthogonality of temperature, moisture, and vapor concentrations in air at ambient pressure will be explored and assessed for specificity of chemical measurements toward a next generation of IMS instruments. Ion mobility spectrometry is central to military preparedness and commercial aviation security with emerging impact in clinical diagnostics and industrial process control. Impacts of these studies should include the education of a new generation of students in gas phase ion-molecule chemistry at ambient pressure and should provide new capabilities for specific measurement challenges within industry and government.