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| Titel |
Atmospheric oxidation of 1,3-butadiene: characterization of gas and aerosol reaction products and implications for PM2.5 |
| VerfasserIn |
M. Jaoui, M. Lewandowski, K. Docherty, J. H. Offenberg, T. E. Kleindienst |
| 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 ; 14, no. 24 ; Nr. 14, no. 24 (2014-12-20), S.13681-13704 |
| Datensatznummer |
250119260
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| Publikation (Nr.) |
 copernicus.org/acp-14-13681-2014.pdf |
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| Zusammenfassung |
Secondary organic aerosol (SOA) was generated by irradiating 1,3-butadiene
(13BD) in the presence of H2O2 or NOx. Experiments were
conducted in a smog chamber operated in either flow or batch mode. A
filter/denuder sampling system was used for simultaneously collecting gas-
and particle-phase products. The chemical composition of the gas phase and
SOA was analyzed using derivative-based methods (BSTFA, BSTFA + PFBHA, or
DNPH) followed by gas chromatography–mass spectrometry (GC–MS) or
high-performance liquid chromatography (HPLC) analysis of the derivative
compounds. The analysis showed the occurrence of more than 60 oxygenated
organic compounds in the gas and particle phases, of which 31 organic
monomers were tentatively identified. The major identified products include
glyceric acid, d-threitol, erythritol, d-threonic acid,
meso-threonic acid, erythrose, malic acid, tartaric acid, and
carbonyls including glycolaldehyde, glyoxal, acrolein, malonaldehyde,
glyceraldehyde, and peroxyacryloyl nitrate (APAN). Some of these were
detected in ambient PM2.5 samples, and could potentially serve as
organic markers of 13BD. Furthermore, a series of oligoesters
were detected and found to be produced through chemical reactions occurring
in the aerosol phase between compounds bearing alcoholic groups and compounds
bearing acidic groups.
SOA was analyzed for organic mass to organic carbon
(OM /OC) ratio, effective enthalpy of vaporization
(Δ Hvapeff), and aerosol yield. The average
OM /OC ratio and SOA density were 2.7 ± 0.09 and
1.2 ± 0.05, respectively. The average Δ Hvapeff was −26.08 ± 1.46 kJ mol−1, a value lower than that
of isoprene SOA. The average laboratory SOA yield measured in this study at
aerosol mass concentrations between 22.5 and 140.2 μg m−3 was
0.025 ± 0.011, a value consistent with the literature (0.021–0.178).
While the focus of this study has been examination of the particle-phase
measurements, the gas-phase photooxidation products have also been examined.
The contribution of SOA products from 13BD oxidation to ambient PM2.5
was investigated by analyzing a series of ambient PM2.5 samples
collected in several locations around the United States. In addition to the
occurrence of several organic compounds in field and laboratory samples,
glyceric acid, d-threitol, erythritol, erythrose, and threonic acid were
found to originate only from the oxidation of 13BD based on our previous
experiments involving chamber oxidation of a series of hydrocarbons. Initial
attempts have been made to quantify the concentrations of these compounds.
The average concentrations of these compounds in ambient PM2.5 samples
from the California Research at the Nexus of Air Quality and Climate Change
(CalNex) study ranged from 0 to approximately 14.1 ng m−3. The
occurrence of several other compounds in both laboratory and field samples
suggests that SOA originating from 13BD oxidation could contribute to the
ambient aerosol mainly in areas with high 13BD emission rates. |
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