In contrast to classical Ion Mobility Spectrometers (IMS) operating at ambient pressure, the High Kinetic Energy Ion Mobility Spectrometer (HiKE-IMS) is operated at reduced pressures of between 10 and 40 mbar and higher reduced electric field strengths of up to 120 Td. Thus, the ion-molecule reactions occurring in the HiKE-IMS can significantly differ from those in classical ambient pressure IMS. In order to predict the ionization pathways of specific analyte molecules, profound knowledge of the reactant ion species generated in HiKE-IMS and their dependence on the ionization conditions is essential. In this work, the formation of positive reactant ions in HiKE-IMS is investigated in detail. On the basis of kinetic and thermodynamic data from the literature, the ion-molecule reactions are kinetically modeled. To verify the model, we present measurements of the reactant ion population and its dependence on the reduced electric field strength, the operating pressure, and the water concentration in the sample gas. All of these parameters significantly affect the reactant ion population formed in HiKE-IMS.

中文翻译：

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高动能离子迁移谱（HiKE-IMS）中的正反应物离子形成。

与在环境压力下运行的传统离子迁移谱仪（IMS）相比，高动能离子迁移谱仪（HiKE-IMS）在10至40 mbar的减压下运行，而降低的电场强度更高，最高可达120 Td。因此，HiKE-IMS中发生的离子-分子反应可能与经典环境压力IMS中的明显不同。为了预测特定分析物分子的电离途径，必须对HiKE-IMS中产生的反应物离子种类及其对电离条件的依赖性有深入的了解。在这项工作中，详细研究了HiKE-IMS中正反应离子的形成。根据文献的动力学和热力学数据，对离子分子反应进行动力学建模。要验证模型，我们介绍了反应物离子数量及其对降低的电场强度，工作压力和样品气体中水浓度的依赖性的测量结果。所有这些参数都会显着影响HiKE-IMS中形成的反应离子总数。