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| Titel |
Reactions of SIV species with organic compounds: formation mechanisms of organo-sulfur derivatives in atmospheric aerosols |
| VerfasserIn |
Monica Passananti, Jing Shang, Yoan Dupart, Sebastien Perrier, Christian George |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250101694
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| Publikation (Nr.) |
 EGU/EGU2015-886.pdf |
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| Zusammenfassung |
| Secondary organic aerosol (SOA) have an important impact on climate, air quality and human
health. However the chemical reactions involved in their formation and growth are not fully
understood or well-constrained in climate models.
It is well known that inorganic sulfur (mainly in oxidation states (+IV) and (+VI)) plays a
key role in aerosol formation, for instance sulfuric acid is known to be a good nucleating gas.
In addition, acid-catalyzed heterogeneous reactions of organic compounds has shown to
produce new particles, with a clear enhancement in the presence of ozone (Iinuma
2013).
Organosulfates have been detected in tropospheric particles and aqueous phases, which
suggests they are products of secondary organic aerosol formation process (Tolocka 2012).
Originally, the production of organosulfates was explained by the esterification reaction of
alcohols, but this reaction in atmosphere is kinetically negligible. Other formation
pathways have been suggested such as hydrolysis of peroxides and reaction of organic
matter with sulfite and sulfate radical anions (SO3-, SO4-) (Nozière 2010), but it
remains unclear if these can completely explain atmospheric organo-sulfur aerosol
loading.
To better understand the formation of organo-sulfur compounds, we started to investigate
the reactivity of SIV species (SO2 and SO32-) with respect to specific functional groups
(organic acids and double bonds) on atmospherically relevant carboxylic acids and alkenes.
The experiments were carried out in the homogeneous aqueous phase and at the
solid-gas interface. A custom built coated-wall flow tube reactor was developed
to control relativity humidity, SO2 concentration, temperature and gas flow rate.
Homogeneous and heterogeneous reaction kinetics were measured and resulting
products were identified using liquid chromatography coupled with an orbitrap mass
spectrometer (LC-HR-MS). The experiments were performed with and without the
presence of ozone in order to evaluate any impact on the SIV oxidation and product
formation.
Preliminary results reveal that oxidation of SIV species can occur under a variety of
atmospherically relevant conditions. Furthermore, LC-HR-MS analysis confirms the
formation of organo-sulfur compounds that could derive from sulfate and/or the
sulfite radical anion. These results elucidate the role of organo-sulfates aqueous and
interfacial chemistry, important for our scientific understanding of atmospheric SOA
formation.
Iinuma Y., Kahnt A., Mutzel A., Böge O., Herrmann H., Environ. Sci. Technol., 2013,
(47), 3639-3647, DOI: 10.1021/es305156z.
Mauldin III R. L., Berndt T., Sipilä M., Paasonen P., Petäjä T., Kim S., Kurtén T.,
Stratmann F., Kerminen V.-M., Kulmala M., Nature, 2012, (488), 193-196, DOI:
10.1038/nature11278.
Nozière B., Ekström S., AlsbergT., Holmström S., Geophys. Res. Lett., 2010, (37), 1-6,
DOI: 10.1029/2009GL041683.
Tolocka M.P., Turpin B., Environ. Sci. Technol., 2012, (46), 7978-7983, DOI:
10.1021/es300651v. |
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