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| Titel |
Characterization of the organic composition of aerosols from Rondônia, Brazil, during the LBA-SMOCC 2002 experiment and its representation through model compounds |
| VerfasserIn |
S. Decesari, S. Fuzzi, M. C. Facchini, M. Mircea, L. Emblico, F. Cavalli, W. Maenhaut, X. Chi, G. Schkolnik, A. Falkovich, Y. Rudich, M. Claeys, V. Pashynska, G. Vas, I. Kourtchev, R. Vermeylen, A. Hoffer, M. O. Andreae, E. Tagliavini, F. Moretti, P. Artaxo |
| 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. 2 ; Nr. 6, no. 2 (2006-02-07), S.375-402 |
| Datensatznummer |
250003414
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| Publikation (Nr.) |
 copernicus.org/acp-6-375-2006.pdf |
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| Zusammenfassung |
| The chemical composition of carbonaceous aerosols collected during the
LBA-SMOCC field experiment, conducted in Rondônia, Brazil, in 2002
during the transition from the dry to the wet season, was investigated by a
suite of state-of-the-art analytical techniques. The period of most intense
biomass burning was characterized by high concentrations of submicron
particles rich in carbonaceous material and water-soluble organic compounds
(WSOC). At the onset of the rainy period, submicron total carbon (TC)
concentrations decreased by about 20 times. In contrast, the concentration
of supermicron TC was fairly constant throughout the experiment, pointing to
a constant emission of coarse particles from the natural background. About 6–8%
of TC (9–11% of WSOC) was speciated at the molecular level by
GC-MS and liquid chromatography. Polyhydroxylated compounds, aliphatic and
aromatic acids were the main classes of compounds accounted for by
individual compound analysis. Functional group analysis by proton NMR and
chromatographic separation on ion-exchange columns allowed characterization
of ca. 50–90% of WSOC into broad chemical classes (neutral species/light
acids/humic-like substances). In spite of the significant change in
the chemical composition of tracer compounds from the dry to the wet period,
the functional groups and the general chemical classes of WSOC changed only
to a small extent. Model compounds representing size-resolved WSOC chemical
composition for the different periods of the campaign are then proposed in
this paper, based on the chemical characterization by both individual
compound analysis and functional group analysis deployed during the
LBA-SMOCC experiment. Model compounds reproduce quantitatively the average
chemical structure of WSOC and can be used as best-guess surrogates in
microphysical models involving organic aerosol particles over tropical areas
affected by biomass burning. |
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