Molecular-Size-Separated Brown Carbon Absorption for Biomass-Burning Aerosol at Multiple Field Sites
| Autor: | Rodney J. Weber, Rebecca A. Washenfelder, Nga L. Ng, Karsten Baumann, Eric S. Edgerton, Robert A. Di Lorenzo, Cora J. Young, A. R. Attwood, Hongyu Guo, Lu Xu |
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| Rok vydání: | 2017 |
| Předmět: |
Canada
010504 meteorology & atmospheric sciences Absorption spectroscopy Air pollution Analytical chemistry 010501 environmental sciences medicine.disease_cause 7. Clean energy 01 natural sciences Absorbance medicine Environmental Chemistry Molecule Biomass Absorption (electromagnetic radiation) 0105 earth and related environmental sciences Aerosols Air Pollutants Chemistry Atmosphere General Chemistry Carbon Aerosol 13. Climate action Environmental chemistry Volatility (chemistry) Mass fraction |
| Zdroj: | Environmental sciencetechnology. 51(6) |
| ISSN: | 1520-5851 |
| Popis: | 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). |
| Databáze: | OpenAIRE |
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