Magnetic Field Enhanced Photoelectron Ionization Source Portable TOF-MS and Its Application in Analysis of Volatile Reduced Sulfur Compounds
10.11895/j.issn.0253-3820.140738
- VernacularTitle:磁增强光电子电离便携式飞行时间质谱仪的研制及其在挥发性还原态硫化物测量中的应用
- Author:
Jinxu LI
;
Keyong HOU
;
Wuduo ZHAO
;
Wendong CHEN
;
Jichun JIANG
;
Wei LIU
;
Qingyun LI
;
Di TIAN
;
Haiyang LI
- Publication Type:Journal Article
- Keywords:
Volatile reduced sulfur compounds;
Magnetic field enhanced photoelectron ionization;
Portable time-of-flight mass spectrometer;
Online monitoring
- From:
Chinese Journal of Analytical Chemistry
2015;(3):444-450
- CountryChina
- Language:Chinese
-
Abstract:
Reduced sulfur compounds ( RSCs) are one of the main pollutant species in the atmosphere, so it is of great significance to develop a rapid and on-line approaches for their detection. In this study, a portable time-of-flight mass spectrometer ( TOF-MS) with magnetic field enhanced photoelectron ionization source was designed to detect RSCs. The photoelectron ionization source was induced from vacuum ultraviolet photons which generated from vacuum ultraviolet (VUV) lamp with energy of 10. 6 eV. The energy of photoelectrons was controlled by adjusting the extraction voltage to produce the photoelectron ionization, and an annular magnet was used in the ionization region to improve the ionization efficiency of photoelectrons. From the simulation result by SIMION software, it was found that the introduction of magnet field made the motion trajectroies of electrons in the helical motion increase and the convergence of electron at the ionization source was achieved. Experimental results showed that after introducing the magnet filed, the sensitivity of H2 S, SO2 and CS2 was improved by a factor of 5. 3, 9. 4 and 6. 9, respectively. With a detection time of 50 s, the limits of detection for H2S, SO2 and CS2 were 0. 14, 0. 52 and 0. 31 mg/m3(S/N=3), respectively. It could be concluded that the portable TOF-MS with magnetic field enhanced photoelectron ionization source has great potential to be applied for on-line monitoring of volatile sulfides at the emission source.
