Department of Chemistry and Laser Chemistry Institute, Fudan University, Shanghai, China.
J Am Soc Mass Spectrom. 2014 Apr;25(4):548-55. doi: 10.1007/s13361-013-0803-x. Epub 2014 Jan 17.
A mesh-electrode linear ion trap (ME-LIT) mass analyzer was developed and its performance was primarily characterized. In conventional linear ion trap mass analyzers, the trapped ions are mass-selected and then ejected in a radial direction by a slot on a trap electrode. The presence of slots can strongly affect the electric field distribution in the ion trapping region and distort the mass analysis performance. To compensate for detrimental electric field effects, the slot is usually designed and fabricated to be as small as possible, and also has very high mechanical accuracy and symmetry. A ME-LIT with several mesh electrodes was built to compensate for the effects caused by slots. Each mesh electrode was fabricated from a plate electrode with a relatively large slot and the slot was covered with a conductive mesh. Our preliminary experimental results show that the ME-LIT could considerably diminish the detrimental electric field effects caused by slots, and increase the mass resolving power and ion detection efficiency. Even with 4-mm-wide slots, a mass resolution in excess of 600 was obtained using the ME-LIT. Mass resolution could be remarkably improved using mesh electrodes in ion traps with asymmetric electrodes. The stability diagram of the ME-LIT was mapped, and highly efficient tandem mass spectrometry was demonstrated. The ME-LIT was qualified as a LIT mass analyzer. The ME-LIT can improve the mass resolution and decrease the requirements of mechanical accuracy and symmetry of slots, so it shows potential for a wide range of practical uses.
开发了一种网电极线性离子阱(ME-LIT)质量分析器,并对其性能进行了初步表征。在传统的线性离子阱质量分析器中,通过在阱电极上的狭缝将被捕获的离子在径向方向上进行质量选择并喷射出去。狭缝的存在会强烈影响离子捕获区域的电场分布并扭曲质量分析性能。为了补偿有害的电场效应,狭缝通常设计和制造得尽可能小,并且具有非常高的机械精度和对称性。构建了具有多个网电极的 ME-LIT 以补偿狭缝引起的影响。每个网电极均由具有较大狭缝的板电极制成,并且狭缝被导电网覆盖。我们的初步实验结果表明,ME-LIT 可以大大减少狭缝引起的有害电场效应,并提高质量分辨率和离子检测效率。即使使用 4mm 宽的狭缝,也可以使用 ME-LIT 获得超过 600 的质量分辨率。在具有非对称电极的离子阱中使用网电极可以显著提高质量分辨率。绘制了 ME-LIT 的稳定性图,并证明了高效的串联质谱。ME-LIT 被认为是一种 LIT 质量分析器。ME-LIT 可以提高质量分辨率并降低对狭缝机械精度和对称性的要求,因此它在广泛的实际应用中显示出潜力。