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פותח על ידי קלירמאש פתרונות בע"מ -
Mössbauer spectroscopic evidence for citrate-bicarbonate-dithionite extraction of maghemite from soils
Year:
1995
Source of publication :
Clays and Clay Minerals
Authors :
פיין, פנחס
;
.
Volume :
43
Co-Authors:
Singer, M.J., Department of Land, Air and Water Resources, University of California, Davis, CA, 95616, United States
Bowen, L.H., Department of Chemistry, North Carolina State University, Raleigh, NC, 27695, United States
Verosub, K.L., Department of Geology, University of California, Davis, CA, 95616, United States
Fine, P., Institute of Soils and Water, Volcani Center, Bet Degan, Israel
TenPas, J., Department of Land, Air and Water Resources, University of California, Davis, CA 95616, United States
Facilitators :
From page:
1
To page:
7
(
Total pages:
7
)
Abstract:
In a previous paper, we used powder X-ray diffraction and changes in magnetic susceptibility to argue the importance of pedogenic maghemite to soils and the efficacy of the chemical extractant citrate-bicarbonate-dithionite (CBD) to preferentially remove pedogenic maghemite from soil samples while not removing coarse-grained magnetite. Although X-ray diffraction provides strong support for this contention, Mössbauer spectroscopy is the method of choice for determining the oxidation state of iron in minerals and for inferring mineralogy of the iron oxide phases. Our objective in this work was to seek confirming evidence of the importance of maghemite as a pedogenic mineral and the usefulness of the CBD procedure in separating pedogenic maghemite from lithogenic magnetite. We present Mössbauer data on magnetic fractions from pre- and post-CBD treated soil samples. Six of the 10 samples had only maghemite as the sextet component and after CBD treatment, four lost between 96 and 100% of the magnetic susceptibility. Two samples were interpreted as highly oxidized magnetite or a mixture of magnetite and maghemite. We cannot distinguish between these with Mössbauer spectroscopy. In the remaining two samples, iron existed as hematite, ilmenite, magnetite and minor (<10%) amounts of maghemite. Our results provide additional support for pedogenic maghemite in soils and for the preferential removal of maghemite by the CBD procedure. © 1995, The Clay Minerals Society.
Note:
Related Files :
citrate/bicarbonate/dithionite procedure
Mossbauer spectroscopy
Soils
soil surveys
Spectroscopic evidence
X ray diffraction
עוד תגיות
תוכן קשור
More details
DOI :
10.1346/CCMN.1995.0430101
Article number:
Affiliations:
Database:
סקופוס
Publication Type:
מאמר
;
.
Language:
אנגלית
Editors' remarks:
ID:
28849
Last updated date:
02/03/2022 17:27
Creation date:
17/04/2018 00:42
Scientific Publication
Mössbauer spectroscopic evidence for citrate-bicarbonate-dithionite extraction of maghemite from soils
43
Singer, M.J., Department of Land, Air and Water Resources, University of California, Davis, CA, 95616, United States
Bowen, L.H., Department of Chemistry, North Carolina State University, Raleigh, NC, 27695, United States
Verosub, K.L., Department of Geology, University of California, Davis, CA, 95616, United States
Fine, P., Institute of Soils and Water, Volcani Center, Bet Degan, Israel
TenPas, J., Department of Land, Air and Water Resources, University of California, Davis, CA 95616, United States
Mössbauer spectroscopic evidence for citrate-bicarbonate-dithionite extraction of maghemite from soils
In a previous paper, we used powder X-ray diffraction and changes in magnetic susceptibility to argue the importance of pedogenic maghemite to soils and the efficacy of the chemical extractant citrate-bicarbonate-dithionite (CBD) to preferentially remove pedogenic maghemite from soil samples while not removing coarse-grained magnetite. Although X-ray diffraction provides strong support for this contention, Mössbauer spectroscopy is the method of choice for determining the oxidation state of iron in minerals and for inferring mineralogy of the iron oxide phases. Our objective in this work was to seek confirming evidence of the importance of maghemite as a pedogenic mineral and the usefulness of the CBD procedure in separating pedogenic maghemite from lithogenic magnetite. We present Mössbauer data on magnetic fractions from pre- and post-CBD treated soil samples. Six of the 10 samples had only maghemite as the sextet component and after CBD treatment, four lost between 96 and 100% of the magnetic susceptibility. Two samples were interpreted as highly oxidized magnetite or a mixture of magnetite and maghemite. We cannot distinguish between these with Mössbauer spectroscopy. In the remaining two samples, iron existed as hematite, ilmenite, magnetite and minor (<10%) amounts of maghemite. Our results provide additional support for pedogenic maghemite in soils and for the preferential removal of maghemite by the CBD procedure. © 1995, The Clay Minerals Society.
Scientific Publication
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