A Miniaturized Fourier Transform Electrostatic Linear Ion Trap Mass Spectrometer: Mass Range and Resolution
A Miniaturized Fourier Transform Electrostatic Linear Ion Trap Mass Spectrometer: Mass Range and Resolution
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DOI：
10.1007/s13361-018-02126-x
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发表时间：
2019-04-01
影响因子：
3.2
通讯作者：
McLuckey, Scott A.
中科院分区：
文献类型：
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作者：
Johnson, Joshua T.;Lee, Kenneth W.;McLuckey, Scott A.
通过减小傅里叶变换静电线性离子阱（FT-ELIT）质谱仪的轴向长度，提高了质谱分辨率（M/M-FWHM）。质量分辨率的增加直接对应于FT-ELIT中轴向离子频率的增加。使用[缓激肽+2H]（2+）和[胰岛素+5H]（5+）的同位素作为测试离子，在5.25与2.625 ELIT中证明了等效瞬态长度的质量分辨率增加。缓激肽和胰岛素都显示出90%的质量分辨率增加，允许在仅300 ms的数据采集后[胰岛素+5H]（5+）同位素的基线分辨率。使用镜切换来捕获轴向注入ELIT的离子，探索了质/荷范围的相对变化。当使用镜切换捕获离子时，对于给定切换时间，FT-ELIT质谱仪中的质/荷范围由快速离子在一次反射后进入和离开阱所需的时间与慢速离子进入阱所需的时间来确定。通过减少FT-ELIT质谱仪的长度，同时保持从离子最初被加速的点到入射镜的恒定距离，对于给定的镜切换时间，仅低m/z限制受到影响。对于这里检查的两个ELIT长度，在任何给定转换时间的有效质量/电荷范围从5.25 ELIT的m/z（低）-8.9*m/z（低）降低到2.625 ELIT的m/z（低）-5.2*m/z（低）。
Mass resolution (M/M-FWHM) was increased by reducing the axial length of a Fourier transform electrostatic linear ion trap (FT-ELIT) mass spectrometer. The increase in mass resolution corresponds directly to increased axial ion frequencies in the FT-ELIT. Increased mass resolution was demonstrated for equivalent transient lengths in a 5.25 versus 2.625 ELIT using the isotopes of [bradykinin+2H](2+) and [insulin+5H](5+) as test ions. Both bradykinin and insulin show mass resolution increases of 90% allowing baseline resolution of the [insulin+5H](5+) isotopes after only 300ms of data acquisition. Relative changes in mass/charge range were explored using mirror switching to trap ions injected axially into the ELIT. When trapping ions using mirror switching, the mass/charge range in a FT-ELIT mass spectrometer for a given switch time is determined by the time required for fast ions to enter and exit the trap after one reflection versus the time it takes for slow ions to enter the trap. By reducing the length of the FT-ELIT mass spectrometer while maintaining a constant distance from the point from which ions are initially accelerated to the entrance mirror, only the low m/z limit is affected for a given mirror switching time. For the two ELIT lengths examined here, the effective mass/charge range at any given switch time is reduced from m/z(low)-8.9*m/z(low) for the 5.25 ELIT to m/z(low)-5.2*m/z(low) for the 2.625 ELIT.