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| Titel |
Laboratory simulation for the aqueous OH-oxidation of methyl vinyl ketone and methacrolein: significance to the in-cloud SOA production |
| VerfasserIn |
X. Zhang, Z. M. Chen, Y. Zhao |
| 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 ; 10, no. 19 ; Nr. 10, no. 19 (2010-10-08), S.9551-9561 |
| Datensatznummer |
250008818
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| Publikation (Nr.) |
 copernicus.org/acp-10-9551-2010.pdf |
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| Zusammenfassung |
| Increasing evidence suggests that secondary organic aerosol (SOA) is formed
through aqueous phase reactions in atmospheric clouds. In the present study,
the aqueous oxidation of methyl vinyl ketone (MVK) and methacrolein (MACR)
via OH radical were investigated, with an emphasis on the composition and
variation of small-molecular-weight organic products. In addition,
high-molecular-weight compounds (HMWs) were found, interpreted as the ion
abundance and time evolution. Our results provide, for the first time to our
knowledge, experimental evidence that aqueous OH-oxidation of MVK
contributes to SOA formation. Further, a mechanism primarily involving
radical processes was proposed to gain a basic understanding of these two
reactions. Based on the assumed mechanism, a kinetic model was developed for
comparison with the experimental results. The model reproduced the observed
profiles of first-generation intermediates, but failed to simulate the
kinetics of most organic acids mainly due to the lack of chemical kinetics
parameters for HMWs. A sensitivity analysis was performed in terms of the
effect of stoichiometric coefficients for precursors on oxalic acid yields
and the result indicates that additional pathways involving HMWs chemistry
might play an important role in the formation of oxalic acid. We suggest
that further study is needed for better understanding the behavior of
multi-functional products and their contribution to the oxalic acid
formation. |
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