Transboundary secondary organic aerosol in western Japan indicated by the δ13C of water-soluble organic carbon and the m/z 44 signal in organic aerosol mass spectra.
Environ Sci Technol
; 48(11): 6273-81, 2014 Jun 03.
Article
em En
| MEDLINE
| ID: mdl-24805054
ABSTRACT
The stable carbon isotope ratio (δ13C) of low-volatile water-soluble organic carbon (LV-WSOC) was measured in filter samples of total suspended particulate matter, collected every 24 h in the winter of 2010 at an urban site and two rural sites in western Japan. Concentrations of the major chemical species in fine aerosol (<1.0 µm) were also measured in real time by aerosol mass spectrometers. The oxidation state of organic aerosol was evaluated using f44; i.e., the proportion of the signal at m/z 44 (CO2+ ions from the carboxyl group) to the sum of all m/z signals in the organic mass spectra. A strong correlation between LV-WSOC and m/z 44 concentrations was observed, which suggested that LV-WSOC was likely to be associated with carboxylic acids in fine aerosol. Plots of δ13C of LV-WSOC versus f44 showed random variation at the urban site and systematic trends at the rural sites. The systematic trends qualitatively agreed with a simple binary mixture model of secondary organic aerosol with background LV-WSOC with an f44 of â¼0.08 and δ13C of -17 or higher. Comparison with reference values suggested that the source of background LV-WSOC was likely to be primary emissions associated with C4 plants.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Compostos Orgânicos
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Isótopos de Carbono
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Monitoramento Ambiental
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Aerossóis
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Poluentes Atmosféricos
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Material Particulado
País/Região como assunto:
Asia
Idioma:
En
Ano de publicação:
2014
Tipo de documento:
Article