|
Hokkaido University Collection of Scholarly and Academic Papers >
Institute of Low Temperature Science >
Peer-reviewed Journal Articles, etc >
Evidence for 13-carbon enrichment in oxalic acid via iron catalyzed photolysis in aqueous phase
| Title: | Evidence for 13-carbon enrichment in oxalic acid via iron catalyzed photolysis in aqueous phase |
| Authors: | Pavuluri, Chandra Mouli Browse this author | | Kawamura, Kimitaka Browse this author →KAKEN DB |
| Issue Date: | 9-Feb-2012 |
| Publisher: | American Geophysical Union |
| Journal Title: | Geophysical Research Letters |
| Volume: | 39 |
| Start Page: | L03802 |
| Publisher DOI: | 10.1029/2011GL050398 |
| Abstract: | To investigate the effect of photochemical aging on the stable carbon isotopic ratio (δ13C) of oxalic acid (OxA), a dominant organic species in atmospheric aerosols, we conducted a laboratory photolysis of OxA under H2O2-Fe3+(Fe2+)-UV system in aqueous phase and measured δ13C of remaining OxA. Our results showed that a significant photolysis of OxA occurred with OH radical but the isotopic fractionation of OxA was insignificant. In contrast, in the presence of Fe3+ (Fe2+), we found a significant enrichment of 13C in remaining OxA. We also found that kinetic isotope effect (KIE) of OxA largely depends on photochemical age (irradiation time) and concentration ratios of OxA to iron; 3.20 ± 0.49‰ (2.18 ± 1.18 ‰) and 21.62 ± 5.41‰ in 90 min and 180 min irradiation, in which OxA and Fe3+ (Fe2+) ratios were 50:1 and 200:1, respectively. The enrichment of 13C in remaining OxA was more significant during the photolysis catalyzed by Fe3+ (7‰) than by Fe2+ (3‰) in 90 min irradiation when OxA and iron ratios are the same (50:1). This study provides a laboratory evidence for the isotopic enrichment of 13C in OxA with photochemical aging. This approach is useful for better interpretation of atmospheric isotopic measurements in terms of the extent of atmospheric processing of aerosols. |
| Rights: | Copyright 2012 by the American Geophysical Union |
| Type: | article |
| URI: | http://hdl.handle.net/2115/49757 |
| Appears in Collections: | 低温科学研究所 (Institute of Low Temperature Science) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
|
Submitter: 河村 公隆
|
