Trimethylamine as Precursor to Secondary Organic Aerosol Formation via Nitrate Radical Reaction in the Atmosphere

• Published in: Environmental science & technology Vol. 42; no. 13; pp. 4689 - 4696
• Main Authors: Silva, Philip J, Erupe, Mark E, Price, Derek, Elias, John, G. J. Malloy, Quentin, Li, Qi, Warren, Bethany, Cocker, David R
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.07.2008
• Subjects: Aerosols; Aerosols - analysis; Aerosols - chemistry; Amines - analysis; Amines - chemistry; Applied sciences; Atmosphere; Atmosphere - chemistry; Characterization of Natural and Affected Environments; Chemical reactions; Environmental science; Exact sciences and technology; Mass Spectrometry; Methylamines - analysis; Nitrates; Nitrates - chemistry; Particulate Matter - analysis; Pollution; Smog; Utah; Winter; Utah; USA, Utah, Logan; Conversion rate; Pollutant formation; Secondary pollutant; Nitrates; Diurnal variation; Precursor; Smog; Aerosols; Air pollution; Oxidation; Kinetics; Mass spectrometry; Nocturnal variation
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/es703016v

Amines in fine particulate matter have been detected and quantified during ambient studies of winter inversions in Logan, UT, using aerosol mass spectrometry. Amine-related compounds account for 0.5–6 µg m−3 of fine particulate mass during some wintertime periods. The amine contributions sometimes show a clear diurnal pattern, reaching peak concentrations during the middle of the night while decreasing during the morning and afternoon. Smog chamber reactions show that the reaction of tertiary amines with nitrate radical can account for this behavior in the atmosphere. The lower bound reaction rate of trimethylamine and nitrate radical is estimated at 4.4 × 10−16 cm3/molecules/s with a conversion rate to the aerosol phase of ∼65%. This suggests that amines could be a contributor to secondary organic aerosol formation in areas where nitrate radical is a significant player in oxidation chemistry.