[DeGouw2003] "Emission sources and ocean uptake of acetonitrile (CH3CN) in the atmosphere",
Journal of geophysical research
, vol. 108, no. D11: American Geophysical Union, pp. 4329, 2003.
Airborne measurements of acetonitrile (CH3CN) were made off the U.S. west coast, over California, and during two transfer flights over the U.S. in April and May of 2002. Acetonitrile was strongly enhanced in the plumes from two forest fires, confirming the usefulness of the measurement as an indicator for biomass burning emissions. The emission ratios relative to CO of acetonitrile in the two plumes were slightly higher than previously reported values for fires burning in other fuel types. No significant acetonitrile release was observed in the Los Angeles basin or from other point sources (ships and a power plant). Acetonitrile concentrations were significantly reduced in the marine boundary layer indicating the presence of an ocean uptake sink. Increased loss of acetonitrile was observed close to the coast, suggesting that acetonitrile was efficiently lost by dissolving in the upwelling ocean water, or by biological processes in the surface water.
[DeGouw2003a] "Validation of proton transfer reaction-mass spectrometry (PTR-MS) measurements of gas-phase organic compounds in the atmosphere during the New England Air Quality Study (NEAQS) in 2002",
Journal of geophysical research
, vol. 108, no. D21: American Geophysical Union, pp. 4682, 2003.
Organic compounds were measured by proton transfer reaction-mass spectrometry (PTR-MS) on board the National Oceanic and Atmospheric Administration's research ship Ronald H. Brown during the New England Air Quality Study (NEAQS) in July and August of 2002. PTR-MS has the potential to measure many important organic species with a fast time response, but its validity has not been proven sufficiently. The results obtained by PTR-MS during NEAQS were compared with those from (oxygenated) hydrocarbon measurements by gas chromatography/mass spectrometry (GC-MS), peroxyacyl nitrate measurements by gas chromatography/electron capture detection, and carboxylic acid measurements by mist chamber/ion chromatography. The PTR-MS and GC-MS data for methanol, acetonitrile, acetone, isoprene, benzene, and toluene agreed within the measurement uncertainties. The comparison for C8 aromatics and acetaldehyde was less quantitative due to calibration inaccuracies. In addition, PTR-MS measured the sum of methyl vinyl ketone and methacrolein at 71 amu, the sum of C9 aromatics at 121 amu, and the sum of monoterpenes at 81 and 137 amu. The PTR-MS signal at 61 amu was found to correlate well with data for acetic acid. The signal at 73 amu correlated reasonably well with methyl ethyl ketone data, but the quantitative disagreement suggested interference from other species, possibly methyl glyoxal. The signal at 77 amu correlated well with data for peroxyacetyl nitrate, and the sensitivity inferred from the field data agreed within 30% with the results from laboratory calibrations. Finally, the signal at 105 amu was attributed to styrene and peroxy isobutyryl nitrate. These results prove that many important organic species can be measured accurately and with a fast response time by PTR-MS.