[Veres2010] "Measurements of gas-phase inorganic and organic acids from biomass fires by negative-ion proton-transfer chemical-ionization mass spectrometry",
Journal of Geophysical Research
, vol. 115, no. D23: American Geophysical Union, pp. D23302, 2010.
Emissions from 34 laboratory biomass fires were investigated at the combustion facility of the U.S. Department of Agriculture Fire Sciences Laboratory in Missoula, Montana. Gas-phase organic and inorganic acids were quantified using negative-ion proton-transfer chemical-ionization mass spectrometry (NI-PT-CIMS), open-path Fourier transform infrared spectroscopy (OP-FTIR), and proton-transfer-reaction mass spectrometry (PTR-MS). NI-PT-CIMS is a novel technique that measures the mass-to-charge ratio (m/z) of ions generated from reactions of acetate (CH3C(O)O−) ions with inorganic and organic acids. The emission ratios for various important reactive acids with respect to CO were determined. Emission ratios for isocyanic acid (HNCO), 1,2 and 1,3-benzenediols (catechol, resorcinol), nitrous acid (HONO), acrylic acid, methacrylic acid, propionic acid, formic acid, pyruvic acid, and glycolic acid were measured from biomass burning. Our measurements show that there is a significant amount of HONO in fresh smoke. The NI-PT-CIMS measurements were validated by comparison with OP-FTIR measurements of HONO and formic acid (HCOOH) and with PTR-MS measurements of HCOOH.
[deGouw2007] "Measurements of volatile organic compounds in the earth's atmosphere using proton-transfer-reaction mass spectrometry.",
Mass Spectrom Rev
, vol. 26, no. 2: Chemical Sciences Division, Earth System Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, Colorado 80305, USA. Jost.firstname.lastname@example.org, pp. 223–257, 2007.
<p>Proton-transfer-reaction mass spectrometry (PTR-MS) allows real-time measurements of volatile organic compounds (VOCs) in air with a high sensitivity and a fast time response. The use of PTR-MS in atmospheric research has expanded rapidly in recent years, and much has been learned about the instrument response and specificity of the technique in the analysis of air from different regions of the atmosphere. This paper aims to review the progress that has been made. The theory of operation is described and allows the response of the instrument to be described for different operating conditions. More accurate determinations of the instrument response involve calibrations using standard mixtures, and some results are shown. Much has been learned about the specificity of PTR-MS from inter-comparison studies as well the coupling of PTR-MS with a gas chromatographic interface. The literature on this issue is reviewed and summarized for many VOCs of atmospheric interest. Some highlights of airborne measurements by PTR-MS are presented, including the results obtained in fresh and aged forest-fire and urban plumes. Finally, the recent work that is focused on improving the technique is discussed.</p>