阶梯电极离子阱质量分析器的结构与性能

摘要

Theoretical study and experimental test of a new ion trap mass analyzer-ladder electrode linear ion trap (LeLIT) were reported. The LeLIT was composed of two pairs of ladder electrodes and one pair of end-electrodes. By optimizing the geometric structure of ladder electrodes, we optimized the electric field distribution for optimum mass analysis. Since the distribution of electric field can be controlled by the adjustment of LeLIT structure, LeLIT have better performance than rectilinear ion trap theoretically. Due to its simpler structure than hyperbolic electrode LIT, LeLIT can be easily built. In this work, the height, width and field ratio were adjusted for optimizing the property of LeLIT, and a mass resolution of 10150 was obtained when the mass scan speed was 225 Da / s for a LeLIT with X0 ×Y0 = 9 mm×5 mm dimension. The preliminary experimental result showed that the LeLIT has proper tandem mass spectrometric performance as any conventional ion trap mass analyzer.%本研究从理论上优化了一种新型结构的线型离子阱质量分析器-阶梯电极离子阱质量分析器，它是由2对阶梯电极与1对端盖电极组成。与传统平板电极矩形离子阱长阶梯电极离子阱相比，具有调节电场分布的优点，同时在几何结构设计上更接近于双曲面电极结构，但比双曲面电极更容易加工。通过改变阶梯电极结构的高度、宽度、场半径比例等几何参数，实现了对离子阱内部电场分布的优化，从而实现离子阱性能的优化。理论模拟研究结果表明，根据几何结构和电场分布优化获得的阶梯电极离子阱质量分析器(X0×Y0=9 mm×5 mm)，可以在225 Da/ s 扫速下获得10150的质量分辨率。阶梯电极离子阱结构简单，分辨能力明显高于矩形离子阱。初步的实验结果表明，阶梯电极离子阱具有较好的串级质谱分析性能。