高灵敏度空间小型线性离子阱质谱分析技术关键理论与实验研究

Linear ion trap mass spectrometer (LIT) have been paid more and more attention in the field of space exploration due to low requirement of vacuum degree, ability of tandem mass spectrum, high signal-to-noise ratio and the simple structure control. The applicant has developed a miniature LIT mass spectrometer prototype based on continuous atmospheric sampling. Under the frequency scanning operation mode, the upper limit of the mass range is up to 2500 Da, and the energy consumption can be reduced by about 2/5 compared with the traditional resonance excitation mode. However, significant degeneration in sensitivity emerges for this device. In view of this problem, this project will be carried out in two aspects: theoretical modeling and experimental verification. First, theoretical models will be established to explore the evolution mechanism and the transient response to different ejection parameters, thus to verify the feasibility of unidirectional ejection on LIT. Second, experimental work will be implemented to verify the theoretical results and the optimal design. The development of this project is helpful to understand the influence of LIT miniaturization on the evolution characteristics of ion motion, and achieve unidirectional eject technology and improve its sensitivity. The results of the project are of great significance and value for promoting miniature LIT mass spectrometer in the field of space applications.

目前，线性离子阱(LIT)质谱计在空间探索领域日益受到重视。申请人开发了一种连续大气压进样小型化LIT样机，质量范围上限达到2500Da，能耗与传统共振激发模式相比，可降低约2/5。但是，质谱计的其它性能，如灵敏度等指标下降较为严重。针对该问题，本项目拟开展理论建模和实验验证两方面的工作，系统研究小型LIT参数和复杂多因素耦合作用对其灵敏度的影响。首先，建立离子运动演化模型，并利用该模型对各种参数下离子运动特征进行仿真，探索在LIT上实现单向弹出的可行性，为小型LIT质谱计的优化设计提供理论依据。其次，根据理论研究结果，对质谱计进行优化设计，并对现有小型LIT质谱计进行改进；然后开展实验，确定其各项性能指标，对理论模型和优化设计进行验证。本项目的开展，有助于深入理解LIT质谱计的小型化对离子动力演化特征的影响，改善其灵敏度，项目成果对推动小型LIT在空间大分子分析领域具有十分重要的意义。

本项目针对小型化线性离子阱灵敏度下降问题，开展了理论建模和实验验证两方面的工作，系统研究了小型LIT参数和复杂多因素耦合作用对其灵敏度的影响。建立了离子运动演化模型，并利用该模型对各种参数下离子运动特征进行仿真，探索在LIT上实现单向弹出的可行性，为小型LIT质谱计的优化设计提供了理论依据。其次，根据理论研究结果，对质谱计进行优化设计，并对现有小型LIT质谱计进行改进；然后开展实验，确定其各项性能指标，对理论模型和优化设计进行验证。本项目的开展，有助于深入理解LIT质谱计的小型化对离子动力演化特征的影响，改善其灵敏度，项目成果对推动小型LIT在空间大分子分析领域具有十分重要的意义。