Alcott, LJ orcid.org/0000-0001-9068-8010, Krause, AJ orcid.org/0000-0002-9771-8101, Hammarlund, EU et al. (10 more authors) (2020) Development of Iron Speciation Reference Materials for Palaeoredox Analysis. Geostandards and Geoanalytical Research, 44 (3). pp. 581-591. ISSN 1639-4488
Abstract
The development and application of geochemical techniques to identify redox conditions in modern and ancient aquatic environments has intensified over recent years. Iron (Fe) speciation has emerged as one of the most widely used procedures to distinguish different redox regimes in both the water column and sediments, and is the main technique used to identify oxic, ferruginous (anoxic, Fe(II) containing) and euxinic (anoxic, sulfidic) water column conditions. However, an international sediment reference material has never been developed. This has led to concern over the consistency of results published by the many laboratories that now utilise the technique. Here, we report an interlaboratory comparison of four Fe speciation reference materials for palaeoredox analysis, which span a range of compositions and reflect deposition under different redox conditions. We provide an update of extraction techniques used in Fe speciation and assess the effects of both test portion mass, and the use of different analytical procedures, on the quantification of different Fe fractions in sedimentary rocks. While atomic absorption spectroscopy and inductively coupled plasma-optical emission spectrometry produced comparable Fe measurements for all extraction stages, the use of ferrozine consistently underestimated Fe in the extraction step targeting mixed ferrous–ferric minerals such as magnetite. We therefore suggest that the use of ferrozine is discontinued for this Fe pool. Finally, we report the combined data of four independent Fe speciation laboratories to characterise the Fe speciation composition of the reference materials. These reference materials are available to the community to provide an essential validation of in-house Fe speciation measurements.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2020 The Authors. Geostandards and Geoanalytical Research published by John Wiley & Sons Ltd on behalf of the International Association of Geoanalysts. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. |
Keywords: | iron speciation, sequential extraction, reference materials, water column redox, total iron, ancient sediments |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Earth Surface Science Institute (ESSI) (Leeds) |
Funding Information: | Funder Grant number Royal Society WM150108 Leverhulme Trust Not Known |
Depositing User: | Symplectic Publications |
Date Deposited: | 07 May 2020 14:29 |
Last Modified: | 30 Dec 2022 16:18 |
Status: | Published |
Publisher: | Wiley |
Identification Number: | 10.1111/ggr.12342 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:159749 |