不同参数四极杆组件宽质量范围性能仿真

Performance Simulation of Quadrupole Assemblies with Different Parameters Over a Wide Mass Range

四极质谱计应用需求的不断扩大对四极杆组件需求量迅速增加,为满足大批量、通用化要求需研发几种固定尺寸的模块化四极杆组件,再设计不同的射频电源来满足应用需求。基于四极电场和离子运动理论,使用离子光学仿真软件SIMION对电场分布和离子运动轨迹进行了建模和计算分析。仿真分析结果表明,在所选定仿真参数下,场半径主要决定大质荷比离子通过率曲线形状,其对不同质荷比离子通过率影响不同,对分辨率的影响随质荷比增大而减小;质荷比越小,离子稳定分离所需杆长越长,达到所需杆长前,离子通过率随杆长增加而减小,分辨率相反;直交比的增加会减小通过率、提高分辨率,对大质荷比段影响更大;频率的增加在全质荷比提高分辨率,增加低质荷比通过率,但显著降低大质荷比通过率;大尺寸杆特别适用于低质荷比离子分析,用于大质荷比时必须采取降低边缘场影响的措施。研究结果可为不同应用目的四极质谱计的设计提供参考。

The continuous expansion of the application demand for quadrupole mass spectrometer has led to a rapid increase in the demand for quadrupole components.In order to meet the requirements,several fixed-size modular quadrupole components need to be developed,and different RF power supplies need to be designed to meet the application requirements.Based on the quadrupole electric field and ion motion theory,the ion optical simulation software SIMION was used to model and calculate the electric field distribution and ion motion trajectory.The simulation analysis results show that under the selected simulation parameters,the field radius mainly determines the shape of the ion transmission probability curve with high mass-to-charge ratio ions,and its impact on the transmission probability varies with different mass-to-charge ratio ions.The impact on resolution decreases as the mass-to-charge ratio increases.The smaller the mass-to-charge ratio,the longer the rod length required for stable ion separation.When the rod length is less than required,the transmission probability decreases with the increase of rod length,and the resolution pattern is opposite.An increase in the U/V will reduce the transmission probability,improve resolution,and have a greater impact on the high mass-to-charge ratio.The increase in frequency will improve the resolution of the wide mass-to-change ratios,increase the ion transmission probability of low mass-to-change ratio,but significantly reduce the ion transmission probability of high mass-tocharge ratio.Large-size quadrupole assembly is particularly suitable for low mass-to-charge ratio ion analysis,and measures must be taken to reduce the influence of edge fields when used for high mass-to-charge ratio ion analysis.The research results can provide a reference for the design of quadrupole mass spectrometers for different application purposes.