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| Titel |
Light-absorbing secondary organic material formed by glyoxal in aqueous aerosol mimics |
| VerfasserIn |
E. L. Shapiro, J. Szprengiel, N. Sareen, C. N. Jen, M. R. Giordano, V. F. McNeill |
| 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 ; 9, no. 7 ; Nr. 9, no. 7 (2009-04-01), S.2289-2300 |
| Datensatznummer |
250007151
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| Publikation (Nr.) |
 copernicus.org/acp-9-2289-2009.pdf |
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| Zusammenfassung |
| Light-absorbing and high-molecular-weight secondary organic products were
observed to result from the reaction of glyoxal in mildly acidic (pH=4)
aqueous inorganic salt solutions mimicking aqueous tropospheric aerosol
particles. High-molecular-weight (500–600 amu) products were observed when
ammonium sulfate ((NH4)2SO4) or sodium chloride (NaCl) was
present in the aqueous phase. The products formed in
(NH4)2SO4 or ammonium nitrate (NH4NO3) solutions
absorb light at UV and visible wavelengths. Substantial absorption at
300–400 nm develops within two hours, and absorption between 400–600 nm
develops within days. Pendant drop tensiometry measurements show that the
products are not surface-active. The experimental results along with ab
initio predictions of the UV/Vis absorption of potential products suggest a
mechanism involving the participation of the ammonium ion. If similar
products are formed in atmospheric aerosol particles, they could change the
optical properties of the seed aerosol over its lifetime. |
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