A vacuum ultraviolet photoionization time-of-flight mass spectrometer with high sensitivity for study of gas-phase radical reaction in a flow tube

Zuoying Wen , Xiaofeng Tang (1) , Chengcheng Wang (2) , Christa Fittschen (3) , Tao Wang , Cuihong Zhang (4) , Jiuzhong Yang (1) , Yang Pan , Fuyi Liu , Weijun Zhang (5)

1 NSRL - National Synchrotron Radiation Laboratory
2 School of Electronic and Information Engineering
3 PC2A - Physicochimie des Processus de Combustion et de l’Atmosphère - UMR 8522
4 USTB - Department of Polymer Science and Engineering
5 Anhui Institute of Optics and Fine Mechanics

Photoionization mass spectrometry (PIMS) 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, LOD ~ 0.8 ppb) and high mass resolution (M/ΔM ~ 2100) has been approached. As representative examples, the self-reaction of the methyl radical, CH 3 , 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.

Mots clés: Photoionization mass spectrometer; radical reaction; kinetics; flow tube; methyl radical; methyl peroxy radical 2

Domaines: Chimie

Zuoying Wen, Xiaofeng Tang, Chengcheng Wang, Christa Fittschen, Tao Wang, et al.. A vacuum ultraviolet photoionization time-of-flight mass spectrometer with high sensitivity for study of gas-phase radical reaction in a flow tube. International Journal of Chemical Kinetics, 2019, 51 (3), pp.178-188. ⟨10.1002/kin.21241⟩. ⟨hal-02321977⟩