当前位置: X-MOL 学术J. Mass Spectrom. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Evaluation of microchannel plate gain drops caused by high ion fluxes in time‐of‐flight mass spectrometry: A novel evaluation method using a multi‐turn time‐of‐flight mass spectrometer
Journal of Mass Spectrometry ( IF 2.3 ) Pub Date : 2021-01-22 , DOI: 10.1002/jms.4706
Hiroshi Kobayashi 1, 2 , Toshinobu Hondo 3, 4 , Michisato Toyoda 1, 4
Affiliation  

Use of a two‐stage microchannel plate (MCP) detector is common in time‐of‐flight (TOF) mass spectrometry because it shows excellent time resolution with sufficient gains. However, the gain drops significantly when the detector detects intense ion fluxes, such as matrix ions, by matrix‐assisted laser desorption/ionization mass spectrometry. As a result, significant ion signals corresponding to analytes, such as proteins, are hidden, thereby hampering the mass spectral interpretation. However, details of this phenomenon have not previously been investigated using ions because of the lack of suitable measurement methods and apparatus. Thus, we herein report a novel method for controlling the TOF of two selected ions, as a function of time differences between each other using a multi‐turn TOF mass spectrometer. This method involves the use of an isotope cluster of ions that fly in a figure‐of‐eight orbit and the extraction of an ion at a given lap number. A series of time differences (∆t) between two ions in a TOF spectrum can be generated using this method. We evaluated the time constants of gain recovery after high ion‐flux detection for two sets of two‐stage MCP detectors to obtain values of 1,600 and 180 μs for channel plate resistances of 500 and 71 MΩ, respectively. The obtained time constants from the gains determined at various values of ∆t were 0.48 and 0.38 fold (for 500 and 71 MΩ, respectively) of the values suggested from the channel plate resistance and capacitance.

中文翻译:

飞行时间质谱法中由高离子通量引起的微通道板增益下降的评估:一种使用多圈飞行时间质谱仪的新颖评估方法

在飞行时间(TOF)质谱中通常使用两级微通道板(MCP)检测器,因为它显示出出色的时间分辨率并具有足够的增益。但是,当检测器通过基质辅助激光解吸/电离质谱法检测到强离子通量(例如基质离子)时,增益会显着下降。结果,对应于诸如蛋白质的分析物的重要离子信号被隐藏,从而妨碍了质谱的解释。但是,由于缺乏合适的测量方法和设备,因此以前尚未使用离​​子研究此现象的细节。因此,我们在此报告了一种使用多圈TOF质谱仪根据彼此之间的时间差来控制两个选定离子的TOF的新颖方法。此方法涉及使用在八字形轨道中飞行的离子同位素簇,并提取给定圈数的离子。一系列时差(∆使用这种方法可以在TOF光谱中的两个离子之间生成t)。我们对两组两级MCP检测器的高离子通量检测后的增益恢复的时间常数进行了评估,以分别获得500和71MΩ的通道板电阻得到1600和180μs的值。从在各种∆t值确定的增益中获得的时间常数是通道板电阻和电容所建议值的0.48倍和0.38倍(分别对于500和71MΩ)。
更新日期:2021-02-09
down
wechat
bug