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| Titel |
Gas/particle partitioning of carbonyls in the photooxidation of isoprene and 1,3,5-trimethylbenzene |
| VerfasserIn |
R. M. Healy, J. C. Wenger, A. Metzger, J. Duplissy, M. Kalberer, J. Dommen |
| 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 ; 8, no. 12 ; Nr. 8, no. 12 (2008-06-26), S.3215-3230 |
| Datensatznummer |
250006227
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| Publikation (Nr.) |
 copernicus.org/acp-8-3215-2008.pdf |
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| Zusammenfassung |
A new denuder-filter sampling technique has been used to investigate the
gas/particle partitioning behaviour of the carbonyl products from the
photooxidation of isoprene and 1,3,5-trimethylbenzene. A series of
experiments was performed in two atmospheric simulation chambers at
atmospheric pressure and ambient temperature in the presence of NOx and
at a relative humidity of approximately 50%. The denuder and filter were
both coated with the derivatizing agent
O-(2,3,4,5,6-pentafluorobenzyl)-hydroxylamine (PFBHA) to enable the efficient
collection of gas- and particle-phase carbonyls respectively. The tubes and
filters were extracted and carbonyls identified as their oxime derivatives
by GC-MS. The carbonyl products identified in the experiments accounted for
around 5% and 10% of the mass of secondary organic aerosol formed from
the photooxidation of isoprene and 1,3,5-trimethylbenzene respectively.
Experimental gas/particle partitioning coefficients were determined for a
wide range of carbonyl products formed from the photooxidation of isoprene
and 1,3,5-trimethylbenzene and compared with the theoretical values based on
standard absorptive partitioning theory. Photooxidation products with a
single carbonyl moiety were not observed in the particle phase, but
dicarbonyls, and in particular, glyoxal and methylglyoxal, exhibited
gas/particle partitioning coefficients several orders of magnitude higher
than expected theoretically. These findings support the importance of
heterogeneous and particle-phase chemical reactions for SOA formation and
growth during the atmospheric degradation of anthropogenic and biogenic
hydrocarbons. |
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