All Supporting Information may be found in the online version of this article.
Speciation and trends of organic nitrogen in southeastern U.S. fine particulate matter (PM2.5)
Article first published online: 21 FEB 2013
©2012. American Geophysical Union. All Rights Reserved.
Journal of Geophysical Research: Atmospheres
Volume 118, Issue 4, pages 1996–2006, 27 February 2013
How to Cite
2013), Speciation and trends of organic nitrogen in southeastern U.S. fine particulate matter (PM2.5), J. Geophys. Res. Atmos., 118, 1996–2006, doi:10.1029/2012JD017868., , , , and (
- Issue published online: 17 APR 2013
- Article first published online: 21 FEB 2013
- Manuscript Accepted: 9 DEC 2012
- Manuscript Revised: 2 DEC 2012
- Manuscript Received: 30 MAR 2012
- organic nitrogen;
- amino acids;
- water-soluble organic compounds;
- atmospheric proteinaceous material;
- heterocyclic amines;
- β-carboline photosensitizers;
 The impacts of meteorology and air quality on the concentrations and relative distributions of free and combined amino acids (FAA; CAA) are evaluated during a month-long sampling campaign at a semiurban site in the southeastern U.S. The average FAA concentration in fine aerosols (PM2.5) was 11 ± 6 ng m–3, while CAA was found to be several times higher at 46 ± 21 ng m–3. Glycine and alanine were the most abundant amino acids, accounting for 48% of FAA and 58% of the CAA, while distinct differences were observed in compound distributions; glutamic acid, aspartic acid, serine, and threonine accounted for a further 29% of FAA and 30% of the total CAA. An intense rainfall event during the campaign demonstrated the significant impact of meteorological and air quality conditions on FAA-CAA concentrations and distributions. Correlative trends with atmospheric oxidant (ozone) and inorganic nitrogen levels suggest an important role for atmospheric processing. The liquid chromatography-mass spectrometry (quadrupole time-of-flight) technique used in this study allowed for detection of coextracted water-soluble organic compounds and characterization of a larger fraction of the organic nitrogen mass. N-heterocyclic compounds were detected in samples from this campaign, indicating a likely biomass burning source contribution for organic nitrogen.