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| Titel |
Heterogeneous uptake of gaseous hydrogen peroxide by Gobi and Saharan dust aerosols: a potential missing sink for H2O2 in the troposphere |
| VerfasserIn |
M. Pradhan, G. Kyriakou, A. T. Archibald, A. C. Papageorgiou, M. Kalberer, R. M. Lambert |
| 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. 15 ; Nr. 10, no. 15 (2010-08-03), S.7127-7136 |
| Datensatznummer |
250008675
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| Publikation (Nr.) |
 copernicus.org/acp-10-7127-2010.pdf |
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| Zusammenfassung |
| The first direct laboratory measurements of gaseous hydrogen peroxide uptake
by authentic Gobi and Saharan dust aerosol particles as a function of
relative humidity (RH) have been carried out in an entrained aerosol flow
tube coupled to a chemical ionization mass spectrometer. Gobi dust shows
uptake coefficients, γH2 O2 = (3.33±0.26) ×10−4
at 15% RH rising to γH2 O2 = (6.03±0.42)
×10−4 at 70% RH; the corresponding values for Saharan dust
are systematically higher (γH2 O2
= (6.20±0.22)×10−4 at 15% RH rising to
γH2 O2 = (9.42±0.41)
×10−4 at 70% RH). High resolution X-ray photoelectron
spectroscopy (XPS) measurements of the surface chemical composition of the
two mineral dust samples together with published water adsorption isotherms
of their principal constituents enables rationalization of these
observations, which are relevant to nighttime tropospheric chemistry. A box
model study performed by incorporating the experimentally determined data
set reveals that uptake of H2O2 onto dust can be an important loss
process for this species which has been, until now, poorly constrained. |
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