Zhong Xuefei, Yi Rong, Holliday Alison E, Chen David D Y
Department of Chemistry, University of British Columbia, Vancouver, BC, Canada V6T 1Z1.
Rapid Commun Mass Spectrom. 2009 Mar;23(5):689-97. doi: 10.1002/rcm.3914.
Three-dimensional computer models of electrospray ionization sources were constructed in COMSOL Multiphysics to solve the static electric fields using finite element methods. The magnitude of the electric field strength for onset of electrospray and optimum signal was calculated under various conditions. The modification of the electric field distribution in the ion source by an atmospheric pressure ion lens was also investigated by plotting the equipotential surfaces, electric field lines and trajectories of charged droplets. Both the calculated and the experimental results demonstrate that the changes in the ion signal detected by the mass spectrometer are attributable to the focusing effect of the ion lens when appropriate voltages are applied on the sprayer and ion lens. The optimum signal was found by setting the sprayer voltage from 3000 to 5000 V while scanning the ion lens voltage. The calculated strengths of the electric field at the sprayer tip for optimum signals are similar although the applied voltages at the sprayer and ion lens are significantly different.
在COMSOL Multiphysics中构建了电喷雾电离源的三维计算机模型，以使用有限元方法求解静电场。计算了在各种条件下电喷雾开始和最佳信号时的电场强度大小。还通过绘制等势面、电场线和带电液滴的轨迹，研究了大气压离子透镜对离子源中电场分布的改变。计算结果和实验结果均表明，当在喷雾器和离子透镜上施加适当电压时，质谱仪检测到的离子信号变化归因于离子透镜的聚焦效应。通过在扫描离子透镜电压时将喷雾器电压设置为3000至5000 V来找到最佳信号。尽管喷雾器和离子透镜上的施加电压有显著差异，但计算得到的最佳信号时喷雾器尖端的电场强度相似。
