Iron Speciation in Fram Strait and Over the Northeast Greenland Shelf: An Inter-Comparison Study of Voltammetric Methods
Competitive ligand exchange – adsorptive cathodic stripping voltammetry (CLE-AdCSV) is a widely used technique to determine dissolved iron (Fe) speciation in seawater, and involves competition for Fe of a known added ligand (AL) with natural organic ligands. Three different ALs were used, 2-(2-thiaz...
Published in: | Frontiers in Marine Science |
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Online Access: | https://oceanrep.geomar.de/id/eprint/51899/ https://oceanrep.geomar.de/id/eprint/51899/2/fmars-07-609379.pdf https://oceanrep.geomar.de/id/eprint/51899/3/Data_Sheet_1_Iron%20Speciation%20in%20Fram%20Strait%20and%20Over%20the%20Northeast%20Greenland%20Shelf%20An%20Inter-Comparison%20Study%20of%20Voltammetric%20Methods.docx https://doi.org/10.3389/fmars.2020.609379 |
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ftoceanrep:oai:oceanrep.geomar.de:51899 2024-02-11T10:03:53+01:00 Iron Speciation in Fram Strait and Over the Northeast Greenland Shelf: An Inter-Comparison Study of Voltammetric Methods Ardiningsih, Indah Zhu, Kechen Lodeiro, Pablo Gledhill, Martha Reichart, Gert-Jan Achterberg, Eric P. Middag, Rob Gerringa, Loes J. A. 2021-01-21 text https://oceanrep.geomar.de/id/eprint/51899/ https://oceanrep.geomar.de/id/eprint/51899/2/fmars-07-609379.pdf https://oceanrep.geomar.de/id/eprint/51899/3/Data_Sheet_1_Iron%20Speciation%20in%20Fram%20Strait%20and%20Over%20the%20Northeast%20Greenland%20Shelf%20An%20Inter-Comparison%20Study%20of%20Voltammetric%20Methods.docx https://doi.org/10.3389/fmars.2020.609379 en eng Frontiers https://oceanrep.geomar.de/id/eprint/51899/2/fmars-07-609379.pdf https://oceanrep.geomar.de/id/eprint/51899/3/Data_Sheet_1_Iron%20Speciation%20in%20Fram%20Strait%20and%20Over%20the%20Northeast%20Greenland%20Shelf%20An%20Inter-Comparison%20Study%20of%20Voltammetric%20Methods.docx Ardiningsih, I., Zhu, K., Lodeiro, P. , Gledhill, M. , Reichart, G. J., Achterberg, E. P. , Middag, R. and Gerringa, L. J. A. (2021) Iron Speciation in Fram Strait and Over the Northeast Greenland Shelf: An Inter-Comparison Study of Voltammetric Methods. Open Access Frontiers in Marine Science, 7 . Art.Nr. 609379. DOI 10.3389/fmars.2020.609379 <https://doi.org/10.3389/fmars.2020.609379>. doi:10.3389/fmars.2020.609379 cc_by_4.0 info:eu-repo/semantics/openAccess Article PeerReviewed 2021 ftoceanrep https://doi.org/10.3389/fmars.2020.609379 2024-01-15T00:22:57Z Competitive ligand exchange – adsorptive cathodic stripping voltammetry (CLE-AdCSV) is a widely used technique to determine dissolved iron (Fe) speciation in seawater, and involves competition for Fe of a known added ligand (AL) with natural organic ligands. Three different ALs were used, 2-(2-thiazolylazo)-p-cresol (TAC), salicylaldoxime (SA) and 1-nitroso-2-napthol (NN). The total ligand concentrations ([L t ]) and conditional stability constants (log K ′ Fe’L ) obtained using the different ALs are compared. The comparison was done on seawater samples from Fram Strait and northeast Greenland shelf region, including the Norske Trough, Nioghalvfjerdsfjorden (79N) Glacier front and Westwind Trough. Data interpretation using a one-ligand model resulted in [L t ] SA (2.72 ± 0.99 nM eq Fe) > [L t ] TAC (1.77 ± 0.57 nM eq Fe) > [L t ] NN (1.57 ± 0.58 nM eq Fe); with the mean of log K ′ Fe’L being the highest for TAC (log ′ K Fe’L(TAC) = 12.8 ± 0.5), followed by SA (log K ′ Fe’L(SA) = 10.9 ± 0.4) and NN (log K ′ Fe’L(NN) = 10.1 ± 0.6). These differences are only partly explained by the detection windows employed, and are probably due to uncertainties propagated from the calibration and the heterogeneity of the natural organic ligands. An almost constant ratio of [L t ] TAC /[L t ] SA = 0.5 – 0.6 was obtained in samples over the shelf, potentially related to contributions of humic acid-type ligands. In contrast, in Fram Strait [L t ] TAC /[L t ] SA varied considerably from 0.6 to 1, indicating the influence of other ligand types, which seemed to be detected to a different extent by the TAC and SA methods. Our results show that even though the SA, TAC and NN methods have different detection windows, the results of the one ligand model captured a similar trend in [L t ], increasing from Fram Strait to the Norske Trough to the Westwind Trough. Application of a two-ligand model confirms a previous suggestion that in Polar Surface Water and in water masses over the shelf, two ligand groups existed, a relatively strong ... Article in Journal/Newspaper Fram Strait glacier Greenland Nioghalvfjerdsfjorden OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Greenland Tac ENVELOPE(-59.517,-59.517,-62.500,-62.500) Nioghalvfjerdsfjorden ENVELOPE(-21.500,-21.500,79.500,79.500) Frontiers in Marine Science 7 |
institution |
Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
op_collection_id |
ftoceanrep |
language |
English |
description |
Competitive ligand exchange – adsorptive cathodic stripping voltammetry (CLE-AdCSV) is a widely used technique to determine dissolved iron (Fe) speciation in seawater, and involves competition for Fe of a known added ligand (AL) with natural organic ligands. Three different ALs were used, 2-(2-thiazolylazo)-p-cresol (TAC), salicylaldoxime (SA) and 1-nitroso-2-napthol (NN). The total ligand concentrations ([L t ]) and conditional stability constants (log K ′ Fe’L ) obtained using the different ALs are compared. The comparison was done on seawater samples from Fram Strait and northeast Greenland shelf region, including the Norske Trough, Nioghalvfjerdsfjorden (79N) Glacier front and Westwind Trough. Data interpretation using a one-ligand model resulted in [L t ] SA (2.72 ± 0.99 nM eq Fe) > [L t ] TAC (1.77 ± 0.57 nM eq Fe) > [L t ] NN (1.57 ± 0.58 nM eq Fe); with the mean of log K ′ Fe’L being the highest for TAC (log ′ K Fe’L(TAC) = 12.8 ± 0.5), followed by SA (log K ′ Fe’L(SA) = 10.9 ± 0.4) and NN (log K ′ Fe’L(NN) = 10.1 ± 0.6). These differences are only partly explained by the detection windows employed, and are probably due to uncertainties propagated from the calibration and the heterogeneity of the natural organic ligands. An almost constant ratio of [L t ] TAC /[L t ] SA = 0.5 – 0.6 was obtained in samples over the shelf, potentially related to contributions of humic acid-type ligands. In contrast, in Fram Strait [L t ] TAC /[L t ] SA varied considerably from 0.6 to 1, indicating the influence of other ligand types, which seemed to be detected to a different extent by the TAC and SA methods. Our results show that even though the SA, TAC and NN methods have different detection windows, the results of the one ligand model captured a similar trend in [L t ], increasing from Fram Strait to the Norske Trough to the Westwind Trough. Application of a two-ligand model confirms a previous suggestion that in Polar Surface Water and in water masses over the shelf, two ligand groups existed, a relatively strong ... |
format |
Article in Journal/Newspaper |
author |
Ardiningsih, Indah Zhu, Kechen Lodeiro, Pablo Gledhill, Martha Reichart, Gert-Jan Achterberg, Eric P. Middag, Rob Gerringa, Loes J. A. |
spellingShingle |
Ardiningsih, Indah Zhu, Kechen Lodeiro, Pablo Gledhill, Martha Reichart, Gert-Jan Achterberg, Eric P. Middag, Rob Gerringa, Loes J. A. Iron Speciation in Fram Strait and Over the Northeast Greenland Shelf: An Inter-Comparison Study of Voltammetric Methods |
author_facet |
Ardiningsih, Indah Zhu, Kechen Lodeiro, Pablo Gledhill, Martha Reichart, Gert-Jan Achterberg, Eric P. Middag, Rob Gerringa, Loes J. A. |
author_sort |
Ardiningsih, Indah |
title |
Iron Speciation in Fram Strait and Over the Northeast Greenland Shelf: An Inter-Comparison Study of Voltammetric Methods |
title_short |
Iron Speciation in Fram Strait and Over the Northeast Greenland Shelf: An Inter-Comparison Study of Voltammetric Methods |
title_full |
Iron Speciation in Fram Strait and Over the Northeast Greenland Shelf: An Inter-Comparison Study of Voltammetric Methods |
title_fullStr |
Iron Speciation in Fram Strait and Over the Northeast Greenland Shelf: An Inter-Comparison Study of Voltammetric Methods |
title_full_unstemmed |
Iron Speciation in Fram Strait and Over the Northeast Greenland Shelf: An Inter-Comparison Study of Voltammetric Methods |
title_sort |
iron speciation in fram strait and over the northeast greenland shelf: an inter-comparison study of voltammetric methods |
publisher |
Frontiers |
publishDate |
2021 |
url |
https://oceanrep.geomar.de/id/eprint/51899/ https://oceanrep.geomar.de/id/eprint/51899/2/fmars-07-609379.pdf https://oceanrep.geomar.de/id/eprint/51899/3/Data_Sheet_1_Iron%20Speciation%20in%20Fram%20Strait%20and%20Over%20the%20Northeast%20Greenland%20Shelf%20An%20Inter-Comparison%20Study%20of%20Voltammetric%20Methods.docx https://doi.org/10.3389/fmars.2020.609379 |
long_lat |
ENVELOPE(-59.517,-59.517,-62.500,-62.500) ENVELOPE(-21.500,-21.500,79.500,79.500) |
geographic |
Greenland Tac Nioghalvfjerdsfjorden |
geographic_facet |
Greenland Tac Nioghalvfjerdsfjorden |
genre |
Fram Strait glacier Greenland Nioghalvfjerdsfjorden |
genre_facet |
Fram Strait glacier Greenland Nioghalvfjerdsfjorden |
op_relation |
https://oceanrep.geomar.de/id/eprint/51899/2/fmars-07-609379.pdf https://oceanrep.geomar.de/id/eprint/51899/3/Data_Sheet_1_Iron%20Speciation%20in%20Fram%20Strait%20and%20Over%20the%20Northeast%20Greenland%20Shelf%20An%20Inter-Comparison%20Study%20of%20Voltammetric%20Methods.docx Ardiningsih, I., Zhu, K., Lodeiro, P. , Gledhill, M. , Reichart, G. J., Achterberg, E. P. , Middag, R. and Gerringa, L. J. A. (2021) Iron Speciation in Fram Strait and Over the Northeast Greenland Shelf: An Inter-Comparison Study of Voltammetric Methods. Open Access Frontiers in Marine Science, 7 . Art.Nr. 609379. DOI 10.3389/fmars.2020.609379 <https://doi.org/10.3389/fmars.2020.609379>. doi:10.3389/fmars.2020.609379 |
op_rights |
cc_by_4.0 info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.3389/fmars.2020.609379 |
container_title |
Frontiers in Marine Science |
container_volume |
7 |
_version_ |
1790600235397939200 |