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Organic compounds present in the natural Amazonian aerosol: Characterization by gas chromatography–mass spectrometry

Graham, Bim and Guyon, Pascal and Taylor, Philip E. and Artaxo, Paulo and Maenhaut, Willy and Glovsky, M. Michael and Flagan, Richard C. and Andreae, Meinrat O. (2003) Organic compounds present in the natural Amazonian aerosol: Characterization by gas chromatography–mass spectrometry. Journal of Geophysical Research D, 108 (D24). Art. No. 4766. ISSN 0148-0227. https://resolver.caltech.edu/CaltechAUTHORS:20141027-134942745

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Abstract

As part of the Large-Scale Biosphere-Atmosphere Experiment in Amazonia (LBA)-Cooperative LBA Airborne Regional Experiment (CLAIRE) 2001 campaign in July 2001, separate day and nighttime aerosol samples were collected at a ground-based site in Amazonia, Brazil, in order to examine the composition and temporal variability of the natural “background” aerosol. We used a high-volume sampler to separate the aerosol into fine (aerodynamic diameter, AD < 2.5 μm) and coarse (AD > 2.5 μm) size fractions and quantified a range of organic compounds in methanolic extracts of the samples by a gas chromatographic-mass spectrometric technique. The carbon fraction of the compounds could account for an average of 7% of the organic carbon (OC) in both the fine and coarse aerosol fractions. We observed the highest concentrations of sugars, sugar alcohols, and fatty acids in the coarse aerosol samples, which suggests that these compounds are associated with primary biological aerosol particles (PBAP) observed in the forest atmosphere. Of these, trehalose, mannitol, arabitol, and the fatty acids were found to be more prevalent at night, coinciding with a nocturnal increase in PBAP in the 2–10 μm size range (predominantly yeasts and other small fungal spores). In contrast, glucose, fructose, and sucrose showed persistently higher daytime concentrations, coinciding with a daytime increase in large fungal spores, fern spores, pollen grains, and, to a lesser extent, plant fragments (generally >20 μm in diameter), probably driven by lowered relative humidity and enhanced wind speeds/convective activity during the day. For the fine aerosol samples a series of dicarboxylic and hydroxyacids were detected with persistently higher daytime concentrations, suggesting that photochemical production of a secondary organic aerosol from biogenic volatile organic compounds may have made a significant contribution to the fine aerosol. Anhydrosugars (levoglucosan, mannosan, galactosan), which are specific tracers for biomass burning, were detected only at low levels in the fine aerosol samples. On the basis of the levoglucosan-to-OC emission ratio measured for biomass burning aerosol, we estimate that an average of ∼16% of the OC in the fine aerosol was due to biomass burning during CLAIRE 2001, indicating that the major fraction was associated with biogenic particles.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1029/2003JD003990DOIArticle
http://onlinelibrary.wiley.com/doi/10.1029/2003JD003990/abstractPublisherArticle
ORCID:
AuthorORCID
Maenhaut, Willy0000-0002-4715-4627
Flagan, Richard C.0000-0001-5690-770X
Andreae, Meinrat O.0000-0003-1968-7925
Additional Information:Copyright 2003 by the American Geophysical Union. Received 19 July 2003; revised 16 September 2003; accepted 30 September 2003; published 18 December 2003. This study was carried out as part of the Large-Scale Atmosphere-Biosphere Experiment in Amazonia (LBA). It was made possible by fundamental support through the Max Planck Society. P. Artaxo acknowledges financial support from “Fundação de Amparo à Pesquisa do Estado de São Paulo”, W. Maenhaut is indebted to the Belgian Federal Office for Scientific, Technical and Cultural Affairs, and the “Fonds voor Wetenschappelijk Onderzoek–Vlaanderen” for research support, and P. Taylor, R. Flagan and M. Glovsky acknowledge support from the Philip Morris External Research Program. We sincerely thank the staff of Manaus Energia who supported us in the course of the measurements through the supply and maintenance of infrastructure.
Funders:
Funding AgencyGrant Number
Max Planck SocietyUNSPECIFIED
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)UNSPECIFIED
Belgian Federal Office for Scientific, Technical and Cultural AffairsUNSPECIFIED
Fonds voor Wetenschappelijk Onderzoek–VlaanderenUNSPECIFIED
Philip Morris External Research ProgramUNSPECIFIED
Subject Keywords:gas chromatography–mass spectrometry, organic aerosol, Amazon, biogenic aerosol, sugars, sugar alcohols
Issue or Number:D24
Classification Code:0305 Atmospheric Composition and Structure: Aerosols and particles (0345, 4801); 0365 Atmospheric Composition and Structure: Troposphere—composition and chemistry; 0315 Atmospheric Composition and Structure: Biosphere/atmosphere interactions
Record Number:CaltechAUTHORS:20141027-134942745
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20141027-134942745
Official Citation:Graham, B., P. Guyon, P. E. Taylor, P. Artaxo, W. Maenhaut, M. M. Glovsky, R. C. Flagan, and M. O. Andreae (2003), Organic compounds present in the natural Amazonian aerosol: Characterization by gas chromatography–mass spectrometry, J. Geophys. Res., 108, 4766, doi:10.1029/2003JD003990, D24.
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:50870
Collection:CaltechAUTHORS
Deposited By: George Porter
Deposited On:27 Oct 2014 21:08
Last Modified:03 Oct 2019 07:27

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