Liu, R.; Guo, Y.; Li, M.; Li, J.; Yang, D.; Hou, K. Development and Application of a Chemical Ionization Focusing Integrated Ionization Source TOFMS for Online Detection of OVOCs in the Atmosphere. Molecules2023, 28, 6600.
Liu, R.; Guo, Y.; Li, M.; Li, J.; Yang, D.; Hou, K. Development and Application of a Chemical Ionization Focusing Integrated Ionization Source TOFMS for Online Detection of OVOCs in the Atmosphere. Molecules 2023, 28, 6600.
Liu, R.; Guo, Y.; Li, M.; Li, J.; Yang, D.; Hou, K. Development and Application of a Chemical Ionization Focusing Integrated Ionization Source TOFMS for Online Detection of OVOCs in the Atmosphere. Molecules2023, 28, 6600.
Liu, R.; Guo, Y.; Li, M.; Li, J.; Yang, D.; Hou, K. Development and Application of a Chemical Ionization Focusing Integrated Ionization Source TOFMS for Online Detection of OVOCs in the Atmosphere. Molecules 2023, 28, 6600.
Abstract
Single photon ionization (SPI) based on vacuum ultraviolet (VUV) lamps has been extensively investigated and applied due to its clean mass spectra as a soft ionization method. However, the photon energy of 10.6 eV and photons flux of 106 photons/s of commercial VUV lamp limits its range of ionizable analytes as well as sensitivity. This work designs a chemical ionization focusing integrated (CIFI) ionization source time-of-flight mass spectrometry (TOFMS) based on VUV lamp for the detection of volatile organic compounds (VOCs) and oxygenated volatile organic compounds (OVOCs). The photoelectrons obtained from the VUV lamp through the photoelectric effect ionized the oxygen in the air to obtain the reagent ions O2+, and segmented quadrupole constituted the ion-molecule-reaction region (IMR) and radially focused the ions using a radio-frequency electric field, which improved the yield and transport efficiency of the sample ions and the sensitivity of mass spectrometry, resulting in 44-fold and 1154-fold increase in signal response to benzene and pentanal, respectively. To verify the reliability of the ionization source, the linear correspondence and repeatability of benzene and pentanal were investigated. Satisfactory dynamic linearity was obtained in the concentration range of 5-50 ppbv, and daytime RSD reached 3.91% and 6.26%, respectively. Finally, the CIFI ionization source TOFMS was applied to the determination of OVOCs, and the LOD of 12 types of OVOCs can reach the pptv level, indicating that the ionization source has the potential for accurate and sensitive online monitoring of atmospheric OVOCs.
Keywords
chemical ionization source; segmented quadrupole; oxygenated volatile organic compounds; chemical ionization; photoionization
Subject
Chemistry and Materials Science, Analytical Chemistry
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
