Electron ionization time-of-flight mass spectrometry (EI-TOF-MS) has been widely used in the fields of chemical, environmental, food, medical and pharmaceutical, etc. Coupling gas chromatography (GC) with EI-TOF-MS yields promising qualitative and quantitative results, and the performance is closely related to with the ion guide devices. A good ion guide device for EI ion source can generate a narrow beam of low-energy ions, resulting in high ion transition efficiency. In this study, an ion transition system for EI ion source with radio frequency quadrupole (RFQ) as the collisional focusing ion guide was developed. The ions in the RFQ could be cooled by collisions with buffer gas molecules and focused to near the axis by a RF field. To determine the parameters of the RFQ, including rod length, rod radius, field radius, RFQ exit orifice diameter, RF frequency, RF amplitude, and other transmission electrode voltages, vacuum design theory, RF quadrupole field theory and SIMION software simulations were applied. The performance of a GC-EI-TOFMS instrument was significantly improved using RFQ as collisional focusing ion guide, and the evaluation results showed that the mass resolution was up to 6500 FWHM (m/z 502), the limit of detection (LOD) was 1 pg of OFN (S/N > 30:1), the mass range was 15–968 amu, the mass accuracy was below 0.01 amu, and the relative standard deviation (RSD) was below 1.5% within one week. This study provided an example to build an ion transition system for mass spectrometry, which had important theoretical and practical significance in design and development of new mass spectrometric instrument.

电子电离飞行时间质谱（EI-TOF-MS）已广泛用于化学，环境，食品，医疗和制药等领域。与EI-TOF-MS耦合的气相色谱（GC）产生了广阔前景定性和定量结果，与离子导向装置的性能密切相关。EI离子源的良好离子导向装置可以产生低能量离子的窄束，从而提高离子迁移效率。在这项研究中，开发了一种以射频四极杆（RFQ）作为碰撞聚焦离子导向器的EI离子源离子迁移系统。RFQ中的离子可通过与缓冲气体分子发生碰撞而冷却，并通过RF场集中到轴附近。要确定RFQ的参数，包括杆长，杆半径，场半径，RFQ出口孔直径，应用了射频频率，射频振幅和其他传输电极电压，真空设计理论，射频四极场理论和SIMION软件仿真。RFQ作为碰撞聚焦离子导向器，GC-EI-TOFMS仪器的性能得到了显着改善，评估结果表明，质量分辨率高达6500 FWHM（m / z 502），检测限（LOD）为1 pg OFN（S / N > 30：1），质量范围为15–968 amu，质量精度低于0.01 amu，相对标准偏差（RSD）在一周内低于1.5％。本研究为建立质谱离子迁移系统提供了实例，对新型质谱仪的设计和开发具有重要的理论和现实意义。