Evaluation of adsorption effects on measurements of ammonia, acetic acid, and methanol
- 27 October 2003
- journal article
- Published by American Geophysical Union (AGU) in Journal of Geophysical Research: Solid Earth
- Vol. 108 (D20)
- https://doi.org/10.1029/2003jd003549
Abstract
We examined how adsorption and desorption of gases from inlets and a cell could affect the accuracy of closed-cell FTIR measurements of carbon dioxide (CO2), carbon monoxide (CO), methane (CH4), nitric oxide (NO), nitrogen dioxide (NO2), methanol (CH3OH), acetic acid (CH3COOH), and ammonia (NH3). When standards were delivered to the cell through a stainless steel inlet, temporarily reduced transmission was observed for CH3OH and NH3. However, a halocarbon wax coated inlet (normally used on the system) had excellent transmission (comparable to room temperature Teflon) for both CH3OH and NH3, even at temperatures as low as 5°C. Thus the wax is valuable for coating sampling system components that cannot be fashioned from Teflon. The instrument had a delayed response (∼10–40 s) for NH3 only, which was attributed to passivation of the Pyrex multipass cell. To determine sampling artifacts that could arise from the complex sample matrix presented by smoke, the closed-cell FTIR system was intercompared with an open-path FTIR system (which is immune to sampling artifacts) in well-mixed smoke. A similar cell passivation delay for NH3 was the only artifact found in this test. Overall, the results suggest that ∼10 s is sufficient to detect >80% of an NH3/CO ratio sampled by our fast-flow, closed-cell system. Longer sampling times or consecutive samples return better results. In field campaigns the closed-cell system sampling times were normally 10 to >100 s so NH3 was probably underestimated by 5–15%.Keywords
This publication has 31 references indexed in Scilit:
- Comprehensive laboratory measurements of biomass‐burning emissions: 1. Emissions from Indonesian, African, and other fuelsJournal of Geophysical Research: Solid Earth, 2003
- Trace gas and particle emissions from fires in large diameter and belowground biomass fuelsJournal of Geophysical Research: Solid Earth, 2003
- Trace gas emissions from the production and use of domestic biofuels in Zambia measured by open‐path Fourier transform infrared spectroscopyJournal of Geophysical Research: Solid Earth, 2003
- Evaluation of inlets used for the airborne measurement of formaldehydeJournal of Geophysical Research: Solid Earth, 2002
- Measurements of excess O3, CO2, CO, CH4, C2H4, C2H2, HCN, NO, NH3, HCOOH, CH3COOH, HCHO, and CH3OH in 1997 Alaskan biomass burning plumes by airborne Fourier transform infrared spectroscopy (AFTIR)Journal of Geophysical Research: Solid Earth, 2000
- Emissions of formaldehyde, acetic acid, methanol, and other trace gases from biomass fires in North Carolina measured by airborne Fourier transform infrared spectroscopyJournal of Geophysical Research: Solid Earth, 1999
- Trace gas emissions from laboratory biomass fires measured by open‐path Fourier transform infrared spectroscopy: Fires in grass and surface fuelsJournal of Geophysical Research: Solid Earth, 1999
- Biomass burning as a source of formaldehyde, acetaldehyde, methanol, acetone, acetonitrile, and hydrogen cyanideGeophysical Research Letters, 1999
- Airborne infrared spectroscopy of 1994 western wildfiresJournal of Geophysical Research: Solid Earth, 1997
- A study of the adsorption of NH3 and SO2 on leaf surfacesAtmospheric Environment (1967), 1989