小型化质谱仪为现场原位检测提供可行方案，在诸多领域具有良好应用前景。但仪器小型化以性能的损失为代价，在现场检测复杂基质背景干扰下，明显暴露出选择性不足的问题，大大限制了其应用。为此本项目围绕提高小质谱离子选择性这一科学目标，结合前期研究基础，做出因小质谱气压升高影响离子运动规律进而使传统隔离方法失效的假设。基于该假设本项目深入展开探索。首先研究高背景气压下四极离子阱内离子运动机理；并开展真实小质谱环境下的气流场静电场耦合仿真；搭建非持续性小型差压真空腔四极杆-离子阱原理样机；在此基础上开发频域任意激励波形编辑技术，实现非目标离子的共振激发，以提高离子隔离分辨与效率；最终在食品安全或疾病标志物筛查等领域进行初步应用验证。本项目可增强对小质谱的理论认知，提高仪器选择性，为现场快速检测提供创新工具。

Mass spectrometer, as a kind of instrument for material analysis through ion manipulation under vacuum, plays an important role in modern chemical analysis. The miniaturized mass spectrometer provides a feasible solution for in-situ analysis and field detection, and it has a good application prospect in the fields of life sciences, food safety, environmental monitoring, national defense security and other fields. However, the miniaturization of the instrument comes at the cost of performance. The problem of insufficient selectivity is obviously exposed under the interference of on-site detection of complex substrates, which greatly limits its application. This project focuses on the scientific goal of improving the ion selectivity of a miniature mass spectrometer. Based on our previous research foundation, we believe that the causes might be the impact from the continuous gas flow and high pressure of miniature mass spectrometer compared to traditional laboratory mass spectrometer. In order to test this hypothesis in this project, we carry out related theoretical, simulation and practical research. First, the mechanism of ion movement in the quadrupole ion trap under high background pressure caused by the miniaturization of the instrument will be studied; and the COMSOL+SIMION-based gas flow field and electrostatic field coupling simulation software is gonging to be developed to simulate the ion movement law in the real miniature mass spectrometer environment; To improve the selectivity and reduce the effects of gas flow, differential pressure chamber quadrupole-linear ion trap miniature mass spectrometer with discontinuous subatmospheric pressure interface will be built; On this basis, an arbitrary isolation waveform editing technology in the frequency domain will be developed to help isolate non-target ions and improve the ion isolation resolution and efficiency of the quadrupole ion trap in the high pressure chamber; Finally, a preliminary application verification will be performed in the fields of food safety or disease marker screening. This project is believed to enhance the theoretical understanding of small-scale mass spectrometry, improve the selectivity of instruments, and provide innovative tools for rapid target screening for on-site applications.