Fundamental investigations of ion mobility and separation of isomers by high resolution ion mobility spectrometry

拟议研究项目的主要目标是开发一种紧凑型高分辨率离子迁移谱仪（IMS），其分辨率为R > 300，检测限低至ppt水平，响应时间短于一秒，同时根据应用情况，不同的非放射性离子源可以轻松地连接到IMS。主要的技术挑战是设计满足上述所有分析要求的紧凑型国际监测系统，以及开发操作该系统所需的复杂电子设备。这包括开发一种低噪声、高增益放大器，在150 kHz时具有1 GV/A，并且可以根据所实现的分辨率轻松调整带宽，用于操作离子快门的快速高压开关以及用于漂移环电极的直接低功率供应的紧凑型高压级联电路。为了优化IMS设计，需要详细的实验表征。此外，分析和数值模型，考虑到所有相关的分析性能的影响，将开发和实验验证。特别是，IMS内的离子传输从电离区域的检测器板将进行数值模拟。然而，对于可行的模拟，瞬态电场的不均匀性，主要是由离子快门和移动离子云，离子放电效应在金属表面，扩散和对流传输现象的离子和中性粒子以及不同的离子源的电离特性，必须仔细考虑。此外，离子密度和离子分布内产生的电离区由不同的离子源将被测量的时刻，离子注入通过快门，并作为可行的初始条件的数值模拟。本研究计划集中于非放射性电子发射器、弱X射线源和用于离子产生的光致电离源。经过连续的优化周期，在项目结束时，将提供一个实验验证的理论模型，描述对分析性能的所有相关影响，并提供一个紧凑的高分辨率可交换离子源IMS。一个可能的项目扩展将集中于面向应用的系统优化，重点是呼吸分析和生物过程监测。此外，纳米电喷雾电离源将耦合到IMS，用于快速分析液体。

The main objective of the proposed research project is the development of a compact high-resolution ion mobility spectrometer (IMS) with a resolving power of R > 300, detection limits down to ppt-levels and fast response times of less than a second while different non-radioactive ion sources can be easily coupled to the IMS depending on the application. The main technical challenges are designing such a compact IMS that meets all the analytical requirements mentioned above and the development of complex electronics required for operating the system. This includes the development of a low-noise, high-gain amplifier with 1 GV/A at 150 kHz and the possibility to easily adjust the bandwidth with respect to the achieved resolving power, fast high-voltage switches for operating the ion shutter and a compact high-voltage cascade circuit for a direct low-power supply of the drift ring electrodes. In order to optimize the IMS design a detailed experimental characterization is needed. Furthermore, analytical and numerical models considering all relevant effects on the analytical performance will be developed and experimentally validated. In particular, the ion transport inside the IMS from the ionization region to the detector plate will be numerically simulated. However, for feasible simulations the transient electrical field inhomogeneities mainly caused by the ion shutter and moving ion clouds, ion discharge effects at metallic surfaces, diffusion and convective transport phenomena of ions and neutrals as well as the ionization properties of different ion sources have to be carefully considered. In addition, the ion density and ion distribution generated inside the ionization region by different ion sources will be measured at the moment of ion injection through the shutter and used as feasible initial conditions for the numerical simulations. This research project concentrates on a non-radioactive electron emitter, a weak x-ray source and a photoionization source for ion generation. After successive optimization cycles both an experimentally validated theoretical model describing all relevant effects on the analytical performance and a compact high-resolution IMS with exchangeable ion sources will be available at the end of the project. A possible project extension would concentrate on application-oriented system optimization with a focus on breath analysis and bioprocess monitoring. Furthermore, a nano-electrospray ionization source will be coupled to the IMS for fast analysis of liquids.