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| Titel |
Polar organic compounds in rural PM2.5 aerosols from K-puszta, Hungary, during a 2003 summer field campaign: Sources and diel variations |
| VerfasserIn |
A. C. Ion, R. Vermeylen, I. Kourtchev, J. Cafmeyer, X. Chi, A. Gelencsér, W. Maenhaut, M. Claeys |
| 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 ; 5, no. 7 ; Nr. 5, no. 7 (2005-07-22), S.1805-1814 |
| Datensatznummer |
250002982
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| Publikation (Nr.) |
 copernicus.org/acp-5-1805-2005.pdf |
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| Zusammenfassung |
| In the present study, we examined PM2.5 continental rural background
aerosols, which were collected during a summer field campaign at
K-puszta, Hungary (4 June-10 July 2003), a mixed coniferous/deciduous
forest site characterized by intense solar radiation during summer. Emphasis
was placed on polar oxygenated organic compounds that provide information on
aerosol sources and source processes. The major components detected at
significant atmospheric concentrations were: (a) photo-oxidation products of
isoprene including the 2-methyltetrols (2-methylthreitol and
2-methylerythritol) and 2-methylglyceric acid, (b) levoglucosan, a
marker for biomass burning, (c) malic acid, an intermediate in the oxidation
of unsaturated fatty acids, and (d) the sugar alcohols, arabitol and
mannitol, markers for fungal spores. Diel patterns with highest
concentrations during day-time were observed for the 2-methyltetrols,
which can be regarded as supporting evidence for their fast photochemical
formation from locally emitted isoprene. In addition, a diel pattern with
highest concentrations during day-time was observed for the fungal markers,
suggesting that the release of fungal fragments that are associated with the
PM2.5 aerosol is enhanced during that time. Furthermore, a diel pattern
was also found for levoglucosan with the highest concentrations at night
when wood burning may take place in the settlements around the sampling
site. In contrast, malic acid did not show day/night differences but was
found to follow quite closely the particulate and organic carbon mass. This
is interpreted as an indication that malic acid is formed in photochemical
reactions which have a much longer overall time-scale than that of isoprene
photo-oxidation, and the sources of its precursors are manifold, including
both anthropogenic and natural emissions. On the basis of the high
concentrations found for the isoprene oxidation products during day-time, it
can be concluded that rapid photo-oxidation of isoprene is an important
atmospheric chemistry process that contributes to secondary organic aerosol
(SOA) formation at K-puszta during summer. |
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