Title: | Direct detection of acetonitrile at the pptv level with photoinduced associative ionization time-of-flight mass spectrometry |
Author(s): | Jiang K; Yu Z; Wei Z; Cheng S; Wang H; Yan Z; Shan L; Huang J; Yang B; Shu J; |
Address: | "National Engineering Laboratory for VOCs Pollution Control Material & Technology, University of Chinese Academy of Sciences, Beijing 101408, People's Republic of China. boyang@ucas.ac.cn" |
ISSN/ISBN: | 1759-9679 (Electronic) 1759-9660 (Linking) |
Abstract: | "Photoionization mass spectrometry (PI-MS) has become a versatile tool in the real-time analysis of volatile organic compounds (VOCs) from the atmosphere or exhaled breath. However, some key species, e.g., acetonitrile, are hard to measure due to their higher ionization energies than photon energy. In this study, the direct and sensitive detection of gaseous acetonitrile based on a photoinduced associative ionization (PAI) reaction was investigated with a laboratory-built PAI time-of-flight mass spectrometer (PAI-TOFMS). By doping CH(2)Cl(2) in the photoionization ion source, the mass signal of acetonitrile that cannot be effectively obtained by photoionization appeared with an extremely high intensity through the PAI reaction between acetonitrile, CH(2)Cl(2), and residual H(2)O in the system. Though the moisture in the sample gas has an evident impact on the detection efficiency of acetonitrile, with a relative signal intensity decreasing from 100% under dry conditions to 60% at saturated relative humidity, excellent detection sensitivity was still obtained for gaseous acetonitrile in different matrixes. The sensitivity calibration experiment showed that the detection sensitivities of acetonitrile in N(2) buffer gas, exhaled gas, and outdoor air were 682.4 +/- 5.2, 17.0 +/- 0.7, and 23.9 +/- 0.2 counts pptv(-1), respectively, with an analysis time of 10 s. The corresponding 3sigma LODs reached 0.22, 8.82, and 6.28 pptv, which are equivalent to 0.40, 16.0, and 11.4 ng m(-3). The performance of the PAI-TOFMS was first demonstrated by analyzing exhaled acetonitrile from healthy non-smokers and smokers and continuous monitoring of acetonitrile in outdoor air. In summary, this study provides a new and highly sensitive method for the real-time detection of acetonitrile through mass spectrometry" |
Keywords: | Mass Spectrometry/methods *Exhalation *Volatile Organic Compounds/analysis Chemical Phenomena Gases; |
Notes: | "PubMed-not-MEDLINEJiang, Kui Yu, Zhangqi Wei, Zhiyang Cheng, Shiyu Wang, Haijie Yan, Zitao Shan, Lixin Huang, Jingyun Yang, Bo Shu, Jinian eng England 2023/01/05 Anal Methods. 2023 Jan 19; 15(3):368-376. doi: 10.1039/d2ay01865a" |