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| Titel |
Secondary organic aerosol formation from the photooxidation of isoprene, 1,3-butadiene, and 2,3-dimethyl-1,3-butadiene under high NOx conditions |
| VerfasserIn |
K. Sato, S. Nakao, C. H. Clark, L. Qi, D. R. Cocker III |
| 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 ; 11, no. 14 ; Nr. 11, no. 14 (2011-07-25), S.7301-7317 |
| Datensatznummer |
250009947
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| Publikation (Nr.) |
 copernicus.org/acp-11-7301-2011.pdf |
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| Zusammenfassung |
| Secondary organic aerosol (SOA) formation from atmospheric oxidation of
isoprene has been the subject of multiple studies in recent years; however,
reactions of other conjugated dienes emitted from anthropogenic sources
remain poorly understood. SOA formation from the photooxidation of isoprene,
isoprene-1-13C, 1,3-butadiene, and 2,3-dimethyl-1,3-butadiene is
investigated for high NOx conditions. The SOA yield measured in the
1,3-butadiene/NOx/H2O2 irradiation system (0.089–0.178) was
close to or slightly higher than that measured with isoprene under similar
NOx conditions (0.077–0.103), suggesting that the photooxidation of
1,3-butadiene is a possible source of SOA in urban air. In contrast, a very
small amount of SOA particles was produced in experiments with
2,3-dimethyl-1,3-butadiene. Off-line liquid chromatography – mass
spectrometry analysis revealed that the signals of oligoesters comprise a
major fraction (0.10–0.33) of the signals of the SOA products observed from
all dienes investigated. The oligoesters originate from the unsaturated
aldehyde gas phase diene reaction products; namely, semi-volatile compounds produced
by the oxidation of the unsaturated aldehyde undergo particle-phase
oligoester formation. Oligoesters produced by the dehydration reaction
between nitrooxypolyol and 2-methylglyceric acid monomer or its oligomer
were also characterized in these experiments with isoprene as the starting
diene. These oligomers are possible sources of the 2-methyltetrols found in
ambient aerosol samples collected under high NOx conditions.
Furthermore, in low-temperature experiments also conducted in this study,
the SOA yield measured with isoprene at 278 K was 2–3 times as high as that
measured at 300 K under similar concentration conditions. Although
oligomerization plays an important role in SOA formation from isoprene
photooxidation, the observed temperature dependence of SOA yield is largely
explained by gas/particle partitioning of semi-volatile compounds. |
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