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| Titel |
Functional group analysis by H NMR/chemical derivatization for the characterization of organic aerosol from the SMOCC field campaign |
| VerfasserIn |
E. Tagliavini, F. Moretti, S. Decesari, M. C. Facchini, S. Fuzzi, W. Maenhaut |
| 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 ; 6, no. 4 ; Nr. 6, no. 4 (2006-03-29), S.1003-1019 |
| Datensatznummer |
250003627
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| Publikation (Nr.) |
 copernicus.org/acp-6-1003-2006.pdf |
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| Zusammenfassung |
| Water soluble organic compounds (WSOC) in aerosol samples collected in the
Amazon Basin in a period encompassing the middle/late dry season and the
beginning of the wet season, were investigated by H NMR spectroscopy. HiVol
filter samples (PM2.5 and PM>2.5) and size-segregated samples from
multistage impactor were subjected to H NMR characterization. The H NMR
methodology, recently developed for the analysis of organic aerosol samples,
has been improved by exploiting chemical methylation of carboxylic groups
with diazomethane, which allows the direct determination of the carboxylic
acid content of WSOC. The content of carboxylic carbons for the different
periods and sizes ranged from 12% to 20% of total measured carbon
depending on the season and aerosol size, with higher contents for the fine
particles in the transition and wet periods with respect to the dry period.
A comprehensive picture is presented of WSOC functional groups in aerosol
samples representative of the biomass burning period, as well as of
transition and semi-clean atmospheric conditions. A difference in
composition between fine (PM2.5) and coarse (PM>2.5) size fractions
emerged from the NMR data, the former showing higher alkylic content, the
latter being largely dominated by R-O-H (or R-O-R') functional groups. Very
small particles (<0.14 μm), however, present higher alkyl-chain
content and less oxygenated carbons than larger fine particles (0.42–1.2 μm). More limited variations were found between the average
compositions in the different periods of the campaign. |
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