Development of Iron Speciation Reference Materials for Palaeoredox Analysis
(2020) In Geostandards and Geoanalytical Research 44(3). p.581-591- 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... (More)
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.
(Less)
- author
- organization
- publishing date
- 2020-09
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- ancient sediments, iron speciation, reference materials, sequential extraction, total iron, water column redox
- in
- Geostandards and Geoanalytical Research
- volume
- 44
- issue
- 3
- pages
- 11 pages
- publisher
- Wiley-Blackwell
- external identifiers
-
- scopus:85087687838
- ISSN
- 1639-4488
- DOI
- 10.1111/ggr.12342
- language
- English
- LU publication?
- yes
- id
- adc7be76-42f3-4992-a5e4-68d98f22913e
- date added to LUP
- 2020-07-23 13:22:06
- date last changed
- 2022-04-18 23:41:37
@article{adc7be76-42f3-4992-a5e4-68d98f22913e,
abstract = {{<p>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.</p>}},
author = {{Alcott, Lewis J. and Krause, Alexander J. and Hammarlund, Emma U. and Bjerrum, Christian J. and Scholz, Florian and Xiong, Yijun and Hobson, Andrew J. and Neve, Lesley and Mills, Benjamin J.W. and März, Christian and Schnetger, Bernhard and Bekker, Andrey and Poulton, Simon W.}},
issn = {{1639-4488}},
keywords = {{ancient sediments; iron speciation; reference materials; sequential extraction; total iron; water column redox}},
language = {{eng}},
number = {{3}},
pages = {{581--591}},
publisher = {{Wiley-Blackwell}},
series = {{Geostandards and Geoanalytical Research}},
title = {{Development of Iron Speciation Reference Materials for Palaeoredox Analysis}},
url = {{http://dx.doi.org/10.1111/ggr.12342}},
doi = {{10.1111/ggr.12342}},
volume = {{44}},
year = {{2020}},
}