Optimized energy dispersive X-ray fluorescence analysis of atmospheric aerosols collected at pristine and perturbed Amazon Basin sites

Autor(es)

Arana, Andrea ^[1] ; Loureiro, Ana L. ^[2] ; Barbosa, Henrique M. J. ^[2] ; Van Grieken, Rene ^[3] ; Artaxo, Paulo ^[2]

Afiliação do(s) autor(es)

^[1] Inst Nacl de Pesquisas da Amazonia, Manaus, Amazonas - Brazil

^[2] Univ Sao Paulo, Inst Fis, BR-05508090 Sao Paulo - Brazil

^[3] Univ Antwerp, Dept Chem, B-2610 Antwerp - Belgium

• Tipo de documento: Artigo Científico
• Fonte: X-RAY SPECTROMETRY; v. 43, n. 4, p. 228-237, JUL-AUG 2014.
• Citações Web of Science: 7

Resumo

Elemental composition of aerosols is important to source apportionment studies and to understand atmospheric processes that influence aerosol composition. Energy dispersive X-ray fluorescence spectroscopy was applied for measuring the elemental composition of Amazonian atmospheric aerosols. The instrument used was a spectrometer Epsilon 5, PANalytical B. V., with tridimensional geometry that reduces the background signal with a polarized X-ray detection. The measurement conditions were optimized for low-Z elements, e. g. Mg, Al, Si, that are present at very low concentrations in the Amazon. From Na to K, our detection limits are about 50% to 75% lower than previously published results for similar instrument. Calibration was performed using Micromatter standards, except for P whose standard was produced by nebulization of an aqueous solution of KH2PO4 at our laboratory. The multi-element reference material National Institute of Standards and Technology-2783 (air particulate filter) was used for evaluating the accuracy of the calibration procedure of the 22 elements in our standard analysis routine, and the uncertainty associated with calibration procedures was evaluated. The overall performance of the instrument and validation of our measurements were assessed by comparison with results obtained from parallel analysis using particle-induced X-ray emission and another Epsilon 5 spectrometer. The elemental composition in 660 samples collected at a pristine site in the Amazon Basin and of 1416 samples collected at a site perturbed by land use change was determined. Our measurements show trace elements associated with biogenic aerosols, soil dust, biomass burning, and sea-salt, even for the very low concentrations as observed in Amazonia. Copyright (C) 2014 John Wiley \& Sons, Ltd. (AU)

• Processo FAPESP: 10/52658-1 - Brazil-UK Network for Investigation of Amazonian Atmospheric Composition and Impacts on Climate
• Beneficiário: Paulo Eduardo Artaxo Netto
• Modalidade de apoio: Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - Regular
• Processo FAPESP: 13/05014-0 - GoAmazon: interação da pluma urbana de Manaus com emissões biogênicas da Floresta Amazônica
• Beneficiário: Paulo Eduardo Artaxo Netto
• Modalidade de apoio: Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - Temático
• Processo FAPESP: 11/50170-4 - Produção de aerossóis secundários na Amazônia e seus efeitos climáticos
• Beneficiário: Paulo Eduardo Artaxo Netto
• Modalidade de apoio: Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - Regular
• Processo FAPESP: 12/14437-9 - Estudo de propriedades físico-químicas de aerossóis de queimadas e forçante radiativa no experimento SAMBBA - the South American Biomass Burning Analysis
• Beneficiário: Paulo Eduardo Artaxo Netto
• Modalidade de apoio: Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - Regular