Dataset Persistent ID
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doi:10.25850/nioz/7b.b.7 |
Publication Date
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2020-12-15 |
Title
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Fe-binding ligands, voltammetric methods comparison - PS100
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Other ID
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DAS:ababf988-f1cf-4f05-8062-19505f922849
DOI:10.25850/nioz/7b.b.7
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Author
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Ardiningsih, Indah (Royal Netherlands Institute for Sea Research) - ORCID: 0000-0002-3537-6927
Zu, Kechen (GEOMAR Helmholtz Centre for Ocean Research Kiel)
Lodeiro, Pablo (GEOMAR Helmholtz Centre for Ocean Research Kiel) - ORCID: 0000-0002-2557-5391
Reichart , Gert-Jan (Royal Netherlands Institute for Sea Research, University of Utrecht) - ORCID: 0000-0002-7256-2243
Achterberg , Eric (GEOMAR Helmholtz Centre for Ocean Research Kiel) - ORCID: 0000-0002-3061-2767
Gledhill , Martha (GEOMAR Helmholtz Centre for Ocean Research Kiel) - ORCID: 0000-0003-3859-2112
Middag, Rob (Royal Netherlands Institute for Sea Research) - ORCID: 0000-0002-3326-530X
Gerringa , Loes (Royal Netherlands Institute for Sea Research) - ORCID: 0000-0002-3139-8352
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Contact
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Use email button above to contact.
Ardiningsih, Indah (NIOZ Royal Netherlands Institute for Sea Research)
Research Data Management (NIOZ Royal Netherlands Institute for Sea Research)
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Description
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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. In this study three different ALs were used, 2-(2-thiazolylazo)-p-cresol (TAC), salicylaldoxime (SA) and 1-nitroso-2-napthol (NN). The total ligand concentrations ([Lt]) 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 [Lt]SA (2.72 ?? 0.99 nM eq Fe) > [Lt]TAC (1.77 ?? 0.57 nM eq Fe) > [Lt]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 [Lt]TAC/[Lt]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 [Lt]TAC/[Lt]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 [Lt], 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 and relatively weak ligand group. The relatively weak ligand group contributed less to the total complexation capacity, hence it could only keep part of Fe released from the 79N Glacier in the dissolved phase. Although the SA method had the lowest detection window compared to the TAC and NN methods, the SA method seemed to detect a wider view of the ligand groups. (2020-08-18)
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Subject
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Earth and Environmental Sciences
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Keyword
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GEOTRACES
Fram strait
Arctic
Iron
Organic ligands
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Producer
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Ardiningsih, Indah (Royal Netherlands Institute for Sea Research)
Zu, Kechen (GEOMAR Helmholtz Centre for Ocean Research Kiel)
Lodeiro, Pablo (GEOMAR Helmholtz Centre for Ocean Research Kiel)
Reichart , Gert-Jan (Royal Netherlands Institute for Sea Research, University of Utrecht)
Achterberg , Eric (GEOMAR Helmholtz Centre for Ocean Research Kiel)
Gledhill , Martha (GEOMAR Helmholtz Centre for Ocean Research Kiel)
Middag, Rob (Royal Netherlands Institute for Sea Research)
Gerringa , Loes (Royal Netherlands Institute for Sea Research)
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Production Date
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2020-12-15
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Contributor
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Hosting Institution : NIOZ Royal Netherlands Institute for Sea Research in cooperation with Utrecht University
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Grant Information
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Indonesia Endowment Fund for Education (LPDP) (Doctoral scholarship awarded to Indah Ardiningsih)
The China Scholarship Council (a scholarship awarded to Kechen Zu)
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Distributor
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Research Data Management (NIOZ Royal Netherlands Institute for Sea Research)
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Distribution Date
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2020-08-18
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Depositor
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Indah Ardiningsih
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Deposit Date
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2020-08-18
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Date of Collection
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Start: 2016-07-22 ; End: 2016-08-31
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