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Titel |
Diel and seasonal variations in the chemical composition of biomass burning aerosol |
VerfasserIn |
A. Hoffer, A. Gelencsér, M. Blazsó, P. Guyon, P. Artaxo, M. O. Andreae |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1680-7316
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Digitales Dokument |
URL |
Erschienen |
In: Atmospheric Chemistry and Physics ; 6, no. 11 ; Nr. 6, no. 11 (2006-08-25), S.3505-3515 |
Datensatznummer |
250004068
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Publikation (Nr.) |
copernicus.org/acp-6-3505-2006.pdf |
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Zusammenfassung |
Fine aerosol particles were collected separately during daytime and
nighttime at a tropical pasture site in Rondônia, Brazil, during the
burning and dry-to-wet transition period in 2002. Total carbon (TC) and
water-soluble organic carbon (WSOC) were measured by evolved gas analysis
(EGA). Based on the thermochemical properties of the fine aerosol, the
relative amounts of the volatile and refractory compounds were estimated. It
was found that the thermally refractory (possibly higher molecular weight)
compounds dominated the TC composition. Their contribution to TC was higher
in the daytime than in the nighttime samples. The relative share of WSOC
also showed a statistically significant diel variation as did its refractory
fraction. Anhydrosugars and phenolic acids were determined by GC-MS and
their diel variation was studied. Based on the decrease of their relative
concentrations between the biomass burning and transition periods and their
distinctly different diel variations, we suggest that the phenolic acids may
undergo chemical transformations in the aerosol phase, possibly towards more
refractory compounds (humic-like substances, HULIS), as has been suggested
previously. These conclusions are supported by the results of the thermally
assisted hydrolysis and methylation gas chromatography-mass spectrometry of
the same filter samples. |
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