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| Titel |
In-cloud processes of methacrolein under simulated conditions – Part 2: Formation of secondary organic aerosol |
| VerfasserIn |
I. Haddad, Yao Liu, L. Nieto-Gligorovski, V. Michaud, B. Temime-Roussel, E. Quivet, N. Marchand, K. Sellegri, A. Monod |
| 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 ; 9, no. 14 ; Nr. 9, no. 14 (2009-07-28), S.5107-5117 |
| Datensatznummer |
250007535
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| Publikation (Nr.) |
 copernicus.org/acp-9-5107-2009.pdf |
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| Zusammenfassung |
| The fate of methacrolein in cloud evapo-condensation cycles was
experimentally investigated. To this end, aqueous-phase reactions of
methacrolein with OH radicals were performed (as described in Liu et al.,
2009), and the obtained solutions were then nebulized and dried into a
mixing chamber. ESI-MS and ESI-MS/MS analyses of the aqueous phase
composition denoted the formation of high molecular weight multifunctional
products containing hydroxyl, carbonyl and carboxylic acid moieties. The
time profiles of these products suggest that their formation can imply
radical pathways. These high molecular weight organic products are certainly
responsible for the formation of secondary organic aerosol (SOA) observed
during the nebulization experiments. The size, number and mass concentration
of these particles increased significantly with the reaction time: after 22 h
of reaction, the aerosol mass concentration was about three orders of
magnitude higher than the initial aerosol quantity. The evaluated SOA yield
ranged from 2 to 12%. These yields were confirmed by another estimation
method based on the hygroscopic and volatility properties of the obtained
SOA measured and reported by Michaud et al. (2009). These results
provide, for the first time to our knowledge, strong experimental evidence
that cloud processes can act, through photooxidation reactions, as important
contributors to secondary organic aerosol formation in the troposphere. |
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