Mirror Switching for High-Resolution Ion Isolation in an Electrostatic Linear Ion Trap
Mirror Switching for High-Resolution Ion Isolation in an Electrostatic Linear Ion Trap
复制标题
用于静电线性离子阱中高分辨率离子隔离的镜面切换
DOI：
10.1021/acs.analchem.9b00874
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发表时间：
2019
影响因子：
7.4
通讯作者：
McLuckey, Scott A.
中科院分区：
文献类型：
--
作者：
Johnson, Joshua T.;Carrick, Ian J.;Eakins, Gregory S.;McLuckey, Scott A.
在静电线性离子阱质谱仪（ELIT）中，通过选择性脉冲的入口和出口离子镜实现离子分离。先前已将镜切换描述为用于捕获ELIT装置中的注入离子的方法。在离子捕获之后，镜切换可以用作用于连续更窄范围的质荷（m/z）比的离子隔离的方法。通过利用ELIT装置中离子的空间分离，入射镜和/或出射镜的脉冲可释放不需要的离子，同时继续存储感兴趣的离子。此外，镜像切换可以重复多次以分离具有非常相似的臂/z值的离子，同时存储离子的损失最小，如通过从两种氨基酸离子的混合物以及[PC P-18：0/22：6]和[PC 19：0/19：0]的等压混合物中分离质子化L-谷氨酰胺和L-赖氨酸（Δ m/z = 0.0364）所证明的（Δm/z= 0.0575）。由于ELIT内的离子包的空间/时间分离而实现了隔离，因此示出了多重反射飞行时间（MR-TOF）质谱以证明在隔离时ELIT中的分离。这里使用5.25 in. ELIT。该分辨率对应于将同等丰度的相邻离子的污染物重叠减少到孤立离子强度的1%或更少所需的fwhm分辨率。
Ion isolation was achieved via selective pulsing of the entrance and exit ion mirrors in an electrostatic linear ion trap mass spectrometer (ELIT). Mirror switching has been described previously as a method for capturing injected ions in ELIT devices. After ion trapping, mirror switching can be used as a method for ion isolation of successively narrower ranges of mass-to-charge (m/z) ratio. By taking advantage of the spatial separation of ions in an ELIT device, pulsing of the entrance and/or exit mirrors can release unwanted ions while continuing to store ions of interest. Furthermore, mirror switching can be repeated multiple times to isolate ions of very similarm/zvalues with minimal loss of the stored ions, as is demonstrated by the isolation of protonatedl-glutamine andl-lysine (Δm/z= 0.0364) from a mixture of the two amino acid ions and the isobaric mixture of [PC P-18:0/22:6] and [PC 19:0/19:0] (Δm/z= 0.0575). As isolation is accomplished due to the spatial/temporal separation of ion packets within the ELIT, multiple reflection-time-of-flight (MR-TOF) mass spectra are shown to demonstrate separation in the ELIT at the time of isolation. An isolation resolution of greater than 35 000 fwhm is demonstrated here using a 5.25 in. ELIT. This resolution corresponds to the fwhm resolution necessary to reduce contaminant overlap of an equally abundant adjacent ion to 1% or less of the isolated ion intensity.