The ionization source is the central system of analytical devices such as mass spectrometers or ion mobility spectrometers. In this study, a recently developed flexible microtube plasma (FμTP) is applied as an ionization source for a custom-made drift tube ion mobility spectrometer (IMS) for the first time. The FµTP is based on a highly miniaturized, robust and a small-footprint dielectric barrier discharge design with an outstanding ionization efficiency. In this study, the experimental setup of the FµTP was further improved upon to achieve optimal coupling conditions in terms of the ion mobility spectrometry sensitivity and the plasma gas consumption. One major focus of this study was the adjustment of the electrical operation parameters, in particular, the high voltage amplitude, frequency and duty cycle, in order to minimize the electric field disturbances and yield higher signals. Additionally, the consumption of helium plasma gas was reduced by refining the FµTP. It was found that the ionization efficiency could be significantly enhanced by increasing the plasma high voltage and through application of a duty cycle up to 90:10. Plasma gas flows could be reduced down to 3 mL min-1 by increasing the plasma high voltage amplitude. Furthermore, a smaller wire electrode design enables the operation of the FµTP with nitrogen and clean air. Moreover, detection limits of a homologous series of ketones in the range of 330 pptv (N2-FµTP, 2-decanone) down to 20 pptv (He-FµTP, 2-octanone) could be reached in the optimized setup. To sum up, this feasibility study demonstrates the potential of the optimized FµTP as a powerful ionization source for ion mobility spectrometry especially with regard to ionization efficiency.

中文翻译：

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作为 ION Mobilityspectrometry 的电离源的柔性微管等离子体 (FμTP) 的逐步优化

电离源是质谱仪或离子迁移谱仪等分析设备的核心系统。在这项研究中，最近开发的柔性微管等离子体 (FμTP) 首次用作定制漂移管离子迁移谱仪 (IMS) 的电离源。FµTP 基于高度微型化、坚固耐用且占地面积小的介质阻挡放电设计，具有出色的电离效率。在本研究中，进一步改进了 FµTP 的实验装置，以在离子迁移谱灵敏度和等离子气体消耗方面实现最佳耦合条件。这项研究的一个主要重点是调整电气操作参数，特别是高压幅度、频率和占空比，以最小化电场干扰并产生更高的信号。此外，通过精炼 FµTP 减少了氦等离子气体的消耗。发现通过增加等离子体高电压和通过应用高达 90:10 的占空比可以显着提高电离效率。通过增加等离子高压振幅，等离子气体流量可降低至 3 mL min-1。此外，更小的电极丝设计使 FµTP 能够在氮气和清洁空气中运行。此外，在优化设置中可以达到 330 pptv（N2-FµTP，2-癸酮）到 20 pptv（He-FµTP，2-辛酮）范围内的同源系列酮的检测限。总结，