摘要
A liquid-microjet(LJ)linear time-of-flight(TOF)mass spectrometer,coupled with a femtosecond laser ionization source,has been designed for direct measurements of mass spectra of liquid aqueous solutions.Two main features of our designed spectrometer involve the coupling of a liquid microjet nozzle to a conventional ion optics and the application of femtosecond pulses for mass spectral ionization.The detailed design,construction,and simulation of this new spectrometer are presented.More importantly,we combined the experimental tests with the simulated electric fields and ion trajectories to investigate the performance of the designed spectrometer,especially the kind of disturbances of the nozzle electric field on the conventional ion optics.In our current design,the optimal E/R(E:extractor,R:repeller)electrode voltage ratio was found to be∼0.71 when the voltages on the R,E and G(ground)electrodes were set to be 1500,1060 and 0 V,respectively,whilst the voltage on the N nozzle electrode was required to be around 1250 V.The capability of the designed spectrometer has been demonstrated by recording the simulated mass spectra of the water,benzene and cytidine with their mass/charge ratios of 18,76 and 243,respectively.This work shall be helpful for the development of new all-liquid-phase mass spectral technology to be employed in the diagnosis of diseases by the mass analysis of human body fluids.
本工作设计了一种基于飞秒激光电离源的液体束线性飞行时间质谱仪,可以用于液体水溶液样品的质谱的直接检测.该质谱仪的两个主要特点包括液体束喷嘴与常规离子透镜的耦合和飞秒激光电离源的应用.本文详细地介绍了该新型质谱仪的设计、构造和模拟.通过结合实验测试与离子透镜的电场和离子轨迹的模拟计算,研究了所述质谱仪的性能,特别阐明了喷嘴电场是如何影响常规离子透镜的电场.模拟结果表明在目前设计下当排斥极、喷嘴电极、加速极和接地极的电极电压分别为1500、1250、1060和0 V时可以获得最优的加速极/排斥极的电压比约为0.71.通过对质荷比为18、76与243所对应的水、苯与胞嘧啶的飞行时间质谱的模拟,进一步验证了该质谱仪的性能.本工作有助于发展新型的全液态相的质谱技术,有望应用于通过人体体液的直接质谱检测来诊断相关疾病.
基金
supported by the Knowledge Innovation Program of Wuhan-Basic Research(Nos.2023020201010084,2022010801010134)
the National Key Research and Development Program of China(No.2019YFA0307700)
the National Natural Science Foundation of China(Nos.12274418,22273116,12074389,11974381,22363011).
