Title: | Molecular-Size-Separated Brown Carbon Absorption for Biomass-Burning Aerosol at Multiple Field Sites |
Author(s): | Di Lorenzo RA; Washenfelder RA; Attwood AR; Guo H; Xu L; Ng NL; Weber RJ; Baumann K; Edgerton E; Young CJ; |
Address: | "Department of Chemistry, Memorial University , St. John's, Newfoundland A1B 3X5, Canada. Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder , Boulder, Colorado 80309, United States. Chemical Sciences Division, Earth System Research Laboratory, National Oceanic and Atmospheric Administration , Boulder, Colorado 80305, United States. Atmospheric Research & Analysis Inc. , Cary, North Carolina 27513, United States" |
ISSN/ISBN: | 1520-5851 (Electronic) 0013-936X (Linking) |
Abstract: | "Biomass burning is a known source of brown carbon aerosol in the atmosphere. We collected filter samples of biomass-burning emissions at three locations in Canada and the United States with transport times of 10 h to >3 days. We analyzed the samples with size-exclusion chromatography coupled to molecular absorbance spectroscopy to determine absorbance as a function of molecular size. The majority of absorption was due to molecules >500 Da, and these contributed an increasing fraction of absorption as the biomass-burning aerosol aged. This suggests that the smallest molecular weight fraction is more susceptible to processes that lead to reduced light absorption, while larger-molecular-weight species may represent recalcitrant brown carbon. We calculate that these large-molecular-weight species are composed of more than 20 carbons with as few as two oxygens and would be classified as extremely low volatility organic compounds (ELVOCs)" |
Keywords: | Aerosols Air Pollutants Atmosphere/chemistry *Biomass Canada *Carbon; |
Notes: | "MedlineDi Lorenzo, Robert A Washenfelder, Rebecca A Attwood, Alexis R Guo, Hongyu Xu, Lu Ng, Nga L Weber, Rodney J Baumann, Karsten Edgerton, Eric Young, Cora J eng Research Support, Non-U.S. Gov't 2017/02/16 Environ Sci Technol. 2017 Mar 21; 51(6):3128-3137. doi: 10.1021/acs.est.6b06160. Epub 2017 Mar 1" |