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A vacuum ultraviolet photoionization time-of-flight mass spectrometer with high sensitivity for study of gas-phase radical reaction in a flow tube |
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| Authors: | Zuoying Wen Xiaofeng Tang Chengcheng Wang Christa Fittschen Tao Wang Cuihong Zhang Jiuzhong Yang Yang Pan Fuyi Liu Weijun Zhang |
| Institution: | 1. Laboratory of Atmospheric Physico-Chemistry, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei, China
Graduate School, University of Science and Technology of China, Hefei, China;2. Laboratory of Atmospheric Physico-Chemistry, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei, China;3. University Lille, PC2A, UMR CNRS-ULille 8522, Villeneuve d'Ascq, France;4. National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, China;5. Laboratory of Atmospheric Physico-Chemistry, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei, China School of Environmental Science and Optoelectronic Technology, University of Science and Technology of China, Hefei, China |
| Abstract: | Photoionization mass spectrometry as a powerful analytical method has been widely utilized and provided valuable insight in the field of gas-phase reactions. Here, a highly sensitive vacuum ultraviolet (VUV) photoionization time-of-flight mass spectrometer combined with a microwave discharge generator and a fast flow tube reactor has been developed to study radical reactions of atmospheric and combustion interests. Two kinds of continuous light sources, the tunable VUV synchrotron radiation at Hefei, China for isomer-specific product detection and a commercial krypton discharge lamp for time-consuming kinetic measurements, are employed as photoionization sources in the apparatus. A multiplexed detection with high sensitivity (the limit of detection ∼0.8 ppb) and high mass resolution (M/ΔM ∼ 2100) has been approached. As representative examples, the self-reaction of the methyl radical, CH3, and the reaction of the methyl radical with molecular oxygen are studied and multiple species including reactive radicals and isomeric/isobaric products are detected and identified. In addition, some preliminary results related to the reaction kinetics are also presented. |
| Keywords: | flow tube kinetics methyl peroxy radical methyl radical Photoionization mass spectrometer radical reaction |