Iron speciation in different Saharan dust advections and effect of the procedural blank on the results from X-ray Absorption Spectroscopy and selective leaching experiments
Iron speciation in different Saharan dust advections and effect of the procedural blank on the results from X-ray Absorption Spectroscopy and selective leaching experiments
In this work, we applied X-ray Absorption Spectroscopy (XAS) and selective leaching experiments for investigating iron speciation in different dust advections collected on different unwashed quartz fiber filters. XAS analysis evidenced a predominance of Fe(III) in 6-fold coordination for Saharan dust and a trend towards Fe(II) and 4-fold coordination in the order: Saharan dust, mixed Saharan, and non-Saharan aerosol samples. The role of the sampling substrate was evaluated explicitly, including in the analysis a set of blank filters. We were able to pinpoint the possible contribution to the overall XAS spectrum of the residual Fe on quartz as the concentration decrease towards the blank value. In particular, the filter substrate showed a negligible effect on the structural trend mentioned above. Furthermore, selective leaching experiments evidenced a predominance of the residual fraction on Fe speciation and indicated the lowest Fe concentrations for which the blank contribution is <20% are 1 μg for the first three steps of the procedure (releasing the acid-labile, reducible and oxidizable phases, respectively) and 10 μg for the last step (dissolving the insoluble residuals).
EXAFS;, Monte Martano (Central Italy), Saharan dust;, XANES, filter blank;, iron speciation;, selective leaching experiments;
Petroselli, Chiara
19266726-2dc0-4790-af77-7ccdc45865eb
Moroni, Beatrice
40dfe2d4-7325-410b-ac6a-ec45846a5485
Crocchianti, Stefano
d55d377c-32eb-4aa4-9940-7193fe9b875c
Selvaggi, Roberta
511445f0-0c9d-4aa8-8e15-7c7dee6c3457
Soggia, Francesco
82549fd2-d21d-462f-9aa9-521fa727298a
Grotti, Marco
0a9de0c4-1d24-4cac-9e6c-b1a514c00944
d'Acapito, F.
27ccf185-47ec-4858-8742-cb5e8cc662f3
Cappelletti, David
a01705e5-ab93-4231-ae3c-1093813a5727
July 2020
Petroselli, Chiara
19266726-2dc0-4790-af77-7ccdc45865eb
Moroni, Beatrice
40dfe2d4-7325-410b-ac6a-ec45846a5485
Crocchianti, Stefano
d55d377c-32eb-4aa4-9940-7193fe9b875c
Selvaggi, Roberta
511445f0-0c9d-4aa8-8e15-7c7dee6c3457
Soggia, Francesco
82549fd2-d21d-462f-9aa9-521fa727298a
Grotti, Marco
0a9de0c4-1d24-4cac-9e6c-b1a514c00944
d'Acapito, F.
27ccf185-47ec-4858-8742-cb5e8cc662f3
Cappelletti, David
a01705e5-ab93-4231-ae3c-1093813a5727
Petroselli, Chiara, Moroni, Beatrice, Crocchianti, Stefano, Selvaggi, Roberta, Soggia, Francesco, Grotti, Marco, d'Acapito, F. and Cappelletti, David
(2020)
Iron speciation in different Saharan dust advections and effect of the procedural blank on the results from X-ray Absorption Spectroscopy and selective leaching experiments.
Atmosphere, 11 (7), [735].
(doi:10.3390/atmos11070735).
Abstract
In this work, we applied X-ray Absorption Spectroscopy (XAS) and selective leaching experiments for investigating iron speciation in different dust advections collected on different unwashed quartz fiber filters. XAS analysis evidenced a predominance of Fe(III) in 6-fold coordination for Saharan dust and a trend towards Fe(II) and 4-fold coordination in the order: Saharan dust, mixed Saharan, and non-Saharan aerosol samples. The role of the sampling substrate was evaluated explicitly, including in the analysis a set of blank filters. We were able to pinpoint the possible contribution to the overall XAS spectrum of the residual Fe on quartz as the concentration decrease towards the blank value. In particular, the filter substrate showed a negligible effect on the structural trend mentioned above. Furthermore, selective leaching experiments evidenced a predominance of the residual fraction on Fe speciation and indicated the lowest Fe concentrations for which the blank contribution is <20% are 1 μg for the first three steps of the procedure (releasing the acid-labile, reducible and oxidizable phases, respectively) and 10 μg for the last step (dissolving the insoluble residuals).
Text
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More information
Accepted/In Press date: 9 July 2020
e-pub ahead of print date: 10 July 2020
Published date: July 2020
Additional Information:
Funding Information:
Funding: This research was funded by the University of Perugia through the FRB2015 grant and by Ministero dell’Istruzione, dell’Università e della Ricerca, AMIS project, through the program “Dipartimenti di Eccellenza—2018–2022”.
Publisher Copyright:
© 2020 by the authors.
Keywords:
EXAFS;, Monte Martano (Central Italy), Saharan dust;, XANES, filter blank;, iron speciation;, selective leaching experiments;
Identifiers
Local EPrints ID: 443542
URI: http://eprints.soton.ac.uk/id/eprint/443542
ISSN: 2073-4433
PURE UUID: fbc50d1d-a3ef-44d9-87a4-cd57a766912a
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Date deposited: 28 Aug 2020 16:31
Last modified: 16 Mar 2024 09:02
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Contributors
Author:
Chiara Petroselli
Author:
Beatrice Moroni
Author:
Stefano Crocchianti
Author:
Roberta Selvaggi
Author:
Francesco Soggia
Author:
Marco Grotti
Author:
F. d'Acapito
Author:
David Cappelletti
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