AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
Organic Nitrogen and Carbon in Atmospheric Aerosols: Concentration, Chemical Composition, and Properties
TIANQU CUI, Paul Selleck, Ying-Hsuan Lin, Kelsey Boulanger, Rachel O'Brien, Zhenfa Zhang, Avram Gold, Melita Keywood, Jesse Kroll, Jason Surratt, University of North Carolina at Chapel Hill
Abstract Number: 370 Working Group: Aerosol Chemistry
Abstract Organic nitrogen (ON) and carbon (OC) represent major components of the global N and C cycles, respectively. A large fraction of ON and OC is found in particulate matter, and as such, is subject to local formation and long-range transport, potentially from anthropogenically-influenced areas to more remote regions. However, very little is known about the sources, transformations, or properties of particulate ON and OC, limiting our understanding of how changes in anthropogenic activity and atmospheric organic chemistry may be affecting the cycling of these important nutrients.
The work presented here involves the determination of the identities, quantities, and key properties of particulate ON and OC in atmospheric aerosols, over a wide geographical and temporal range. Coverage of such a range will be achieved by analyzing previously-collected, archived filter samples from a number of locations worldwide. Sites associated with air-studying campaigns vary greatly in terms of geographical conditions and anthropogenic influence, ranging from an urban/polluted area (CalNex 2010, Pasadena, CA), to suburban/rural areas influenced by urban outflow or biomass burning (SOAS 2013, Look Rock, TN) to a very remote marine site (Cape Grim, Tasmania, Australia). At this last site, PM10 high-volume filter samples collected continuously since 1978, to our knowledge are the longest-running continual archive of aerosol particles monitored under clean background conditions. Samples are chemically characterized by (1) ultra performance liquid chromatography coupled to electrospray ionization high-resolution quadrupole time-of-flight mass spectrometry and diode array detection, (2) gas chromatography interfaced with electron ionization mass spectrometry with prior trimethylsilylation, and (3) aerosol mass spectrometry. Preliminary findings show excellent identification of particulate ON species and a number of known secondary organic aerosol (SOA) tracers derived from biogenic and anthropogenic volatile organic compounds at the molecular level, enabling us to further investigate their quantities, trends and properties.