| Title: | "Abiotic methyl bromide formation from vegetation, and its strong dependence on temperature" |
| Author(s): | Wishkerman A; Gebhardt S; McRoberts CW; Hamilton JT; Williams J; Keppler F; |
| Address: | "Max Planck Institute for Chemistry, J. J. Becherweg 27, 55128 Mainz, Germany. wishker@mpch-mainz.mpg.de" |
| ISSN/ISBN: | 0013-936X (Print) 0013-936X (Linking) |
| Abstract: | "Methyl bromide (CH3Br) is the most abundant brominated organic compound in the atmosphere. It is known to originate from natural and anthropogenic sources, although many uncertainties remain regarding strengths of both sources and sinks and the processes leading to its formation. In this study a potential new CH3Br source from vegetation has been examined, analogous to the recently discovered abiotic formation of methyl chloride from plant pectin. Several plant samples with known bromine content, including ash (Fraxinus excelsior), saltwort (Batis maritima), tomato reference material (NIST-1573a), hay reference material (IAEA V-10), and also bromine enriched pectin, were incubated in the temperature range of 25-50 degrees C and analyzed for CH3Br emission using gas chromatography/mass spectrometry. All plant samples inspected showed an exponential increase in CH3Br emission as a function of temperature increase, i.e., emissions were observed to approximately double with every 5 degrees C rise in temperature. Next to temperature, it was found that emissions of CH3Br were also dependent on the bromine content of the plants. The highest CH3Br release rates were found for the saltwort which contained the highest bromine concentration. Arrhenius plots confirmed that the observed emissions were from an abiotic origin. The contribution of abiotic CH3Br formation from vegetation to the global budget will vary geographically as a result of regional differences in both temperature and bromide content of terrestrial plants" |
| Keywords: | "Bromine/metabolism Chlorine/metabolism Desiccation Environment Fraxinus/chemistry Hydrocarbons, Brominated/*analysis Kinetics Solanum lycopersicum/chemistry Methyl Chloride/analysis Pectins/chemistry Plant Leaves/chemistry Plants/*chemistry *Temperature T;" |
| Notes: | "MedlineWishkerman, Asher Gebhardt, Sarah McRoberts, Colin W Hamilton, John T G Williams, Jonathan Keppler, Frank eng Research Support, Non-U.S. Gov't 2008/10/16 Environ Sci Technol. 2008 Sep 15; 42(18):6837-42. doi: 10.1021/es800411j" |
