Department of Mechanical and Industrial Engineering , University of Toronto , Toronto , ON M5S 3G8 , Canada.
Anal Chem. 2018 Mar 6;90(5):3036-3044. doi: 10.1021/acs.analchem.7b04356. Epub 2018 Jan 8.
A completely new ICP torch for optical/mass spectrometry is introduced with a conical geometry leading to significant reduction in gas and power consumption. As a new holistic methodology, the torch has been designed on the basis of fluid flow patterns, heat transfer, plasma physics, and analytical performance. Computer simulations, capable of accounting for magneto-hydrodynamic effects, have been used to optimize torch geometry. The result is a "conical" torch with up to 70% reduction in argon flow and more than 4 times power density compared with traditional "cylindrical" torches. Based on experimental measurements, these features lead to a stable plasma with 1000-1700K higher excitation/rotational temperature and a 5-fold increase in electron number density compared to common torches. Interferences from easily ionizable elements (e.g., Na) are also observed to be minimized due to 3 times higher robustness (Mg II/Mg I ratio). Eventually, analytical parameters including detection limits for multielement analysis indicate comparable/better performance of the new torch in comparison with conventional torches.
一种全新的用于光学/质谱分析的 ICP 炬焰被引入，其锥形几何形状显著降低了气体和功耗。作为一种全新的整体方法，该炬焰是基于流体流动模式、传热、等离子物理和分析性能设计的。能够考虑磁流体动力学效应的计算机模拟被用于优化炬焰几何形状。结果是一种“锥形”炬焰，与传统的“圆柱形”炬焰相比，氩气流减少了 70%，功率密度提高了 4 倍以上。基于实验测量，这些特性导致等离子体更稳定，激发/旋转温度比普通炬焰高 1000-1700K，电子数密度增加了 5 倍。由于 3 倍更高的稳定性（Mg II/Mg I 比），容易电离的元素（如 Na）的干扰也被观察到最小化。最终，多元素分析的检测限等分析参数表明，与传统炬焰相比，新型炬焰的性能相当或更好。
