Using collision-induced dissociation to constrain sensitivity of ammonia chemical ionization mass spectrometry (NH 4 + CIMS) to oxygenated volatile organic compounds
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amt-12-1861-2019.pdf
Description
Published version
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378.98 KB
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Adobe PDF
Checksum (MD5)
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Author(s)
Koss, Abigail R.
Lim, Christopher Yung-Ta
Rowe, James Clifford.
Kroll, Jesse
Date Issued
March 2019
Journal
Atmospheric Measurement Techniques
Publisher
Copernicus GmbH
Citation
Zaytsev, Alexander et al. “Using collision-induced dissociation to constrain sensitivity of ammonia chemical ionization mass spectrometry (NH 4 + CIMS) to oxygenated volatile organic compounds” Atmospheric Measurement Techniques, vol. 12, no. 3, 2019, pp. 1861-1870 © 2019 The Author(s)
Version
Final published version
Abstract
Chemical ionization mass spectrometry (CIMS) instruments routinely detect hundreds of oxidized organic compounds in the atmosphere. A major limitation of these instruments is the uncertainty in their sensitivity to many of the detected ions. We describe the development of a new highresolution time-of-flight chemical ionization mass spectrometer that operates in one of two ionization modes: Using either ammonium ion ligand-switching reactions such as for NHC 4 CIMS or proton transfer reactions such as for protontransfer-reaction mass spectrometer (PTR-MS). Switching between the modes can be done within 2 min. The NH+4 CIMS mode of the new instrument has sensitivities of up to 67 000 dcps ppbv..1 (duty-cycle-corrected ion counts per second per part per billion by volume) and detection limits between 1 and 60 pptv at 2σ for a 1 s integration time for numerous oxygenated volatile organic compounds. We present a mass spectrometric voltage scanning procedure based on collision-induced dissociation that allows us to determine the stability of ammonium-organic ions detected by the NH+4 CIMS instrument. Using this procedure, we can effectively constrain the sensitivity of the ammonia chemical ionization mass spectrometer to a wide range of detected oxidized volatile organic compounds for which no calibration standards exist. We demonstrate the application of this procedure by quantifying the composition of secondary organic aerosols in a series of laboratory experiments.
MIT Department
Massachusetts Institute of Technology. Department of Civil and Environmental Engineering
Terms of Use
Creative Commons Attribution 4.0 International license
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.5194/AMT-12-1861-2019
