Measurement of iron chemical speciation in seawater at 4°C: The use of competitive ligand exchange-adsorptive cathodic stripping voltammetry
Iron is mostly bound to poorly characterised organic ligands; thus, organic ligands are paramount in defining Fe biogeochemical cycling and its control on oceanic primary productivity. Since 1994, Fe chemical speciation has been determined by Competitive Ligand Exchange-Adsorptive Cathodic Stripping...
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ftunivtsydney:oai:opus.lib.uts.edu.au:10453/27431 2023-05-15T18:25:43+02:00 Measurement of iron chemical speciation in seawater at 4°C: The use of competitive ligand exchange-adsorptive cathodic stripping voltammetry Hassler, CS Legiret, FE Butler, ECV 2013-02-01 application/pdf http://hdl.handle.net/10453/27431 unknown Marine Chemistry 10.1016/j.marchem.2012.12.007 Marine Chemistry, 2013, 149 pp. 63 - 73 0304-4203 http://hdl.handle.net/10453/27431 Oceanography Journal Article 2013 ftunivtsydney 2022-03-13T13:26:46Z Iron is mostly bound to poorly characterised organic ligands; thus, organic ligands are paramount in defining Fe biogeochemical cycling and its control on oceanic primary productivity. Since 1994, Fe chemical speciation has been determined by Competitive Ligand Exchange-Adsorptive Cathodic Stripping Voltammetry (CLE-AdCSV) at room temperature. However, chemical speciation is strongly dependent on temperature and some organic ligands can be temperature sensitive. Here, we compare the use of the CLE-AdCSV at room temperature and at 4°C-a temperature closer to that found in the Southern Ocean, one of the largest iron-limited regions. For both temperatures, similar detection limits and total Fe concentrations were found. However, at 4°C the analytical detection window (αFe(TAC)2) was shifted by 1.4-fold towards the detection of weaker ligands, resulting in up to 2-fold lower ligand concentrations as well as a 2- to 5-fold and 10- to70-fold lower conditional stability constants with inorganic Fe (Fe') and Fe(III), respectively. As a result, the Fe' concentration at 4°C was 2-fold greater, resulting in direct implication for Fe bioavailability. Results show that difference in Fe chemical speciation at 4°C was not solely explained by temperature effect on thermodynamics with the exchange ligands or the diffusion of the electroactive complex towards the Hg drop. Lowering analytical window during analysis at room temperature is proposed as a first estimate of temperature effect on iron chemical speciation. © 2013 Elsevier B.V. Article in Journal/Newspaper Southern Ocean University of Technology Sydney: OPUS - Open Publications of UTS Scholars Southern Ocean Tac ENVELOPE(-59.517,-59.517,-62.500,-62.500) |
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University of Technology Sydney: OPUS - Open Publications of UTS Scholars |
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Oceanography |
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Oceanography Hassler, CS Legiret, FE Butler, ECV Measurement of iron chemical speciation in seawater at 4°C: The use of competitive ligand exchange-adsorptive cathodic stripping voltammetry |
topic_facet |
Oceanography |
description |
Iron is mostly bound to poorly characterised organic ligands; thus, organic ligands are paramount in defining Fe biogeochemical cycling and its control on oceanic primary productivity. Since 1994, Fe chemical speciation has been determined by Competitive Ligand Exchange-Adsorptive Cathodic Stripping Voltammetry (CLE-AdCSV) at room temperature. However, chemical speciation is strongly dependent on temperature and some organic ligands can be temperature sensitive. Here, we compare the use of the CLE-AdCSV at room temperature and at 4°C-a temperature closer to that found in the Southern Ocean, one of the largest iron-limited regions. For both temperatures, similar detection limits and total Fe concentrations were found. However, at 4°C the analytical detection window (αFe(TAC)2) was shifted by 1.4-fold towards the detection of weaker ligands, resulting in up to 2-fold lower ligand concentrations as well as a 2- to 5-fold and 10- to70-fold lower conditional stability constants with inorganic Fe (Fe') and Fe(III), respectively. As a result, the Fe' concentration at 4°C was 2-fold greater, resulting in direct implication for Fe bioavailability. Results show that difference in Fe chemical speciation at 4°C was not solely explained by temperature effect on thermodynamics with the exchange ligands or the diffusion of the electroactive complex towards the Hg drop. Lowering analytical window during analysis at room temperature is proposed as a first estimate of temperature effect on iron chemical speciation. © 2013 Elsevier B.V. |
format |
Article in Journal/Newspaper |
author |
Hassler, CS Legiret, FE Butler, ECV |
author_facet |
Hassler, CS Legiret, FE Butler, ECV |
author_sort |
Hassler, CS |
title |
Measurement of iron chemical speciation in seawater at 4°C: The use of competitive ligand exchange-adsorptive cathodic stripping voltammetry |
title_short |
Measurement of iron chemical speciation in seawater at 4°C: The use of competitive ligand exchange-adsorptive cathodic stripping voltammetry |
title_full |
Measurement of iron chemical speciation in seawater at 4°C: The use of competitive ligand exchange-adsorptive cathodic stripping voltammetry |
title_fullStr |
Measurement of iron chemical speciation in seawater at 4°C: The use of competitive ligand exchange-adsorptive cathodic stripping voltammetry |
title_full_unstemmed |
Measurement of iron chemical speciation in seawater at 4°C: The use of competitive ligand exchange-adsorptive cathodic stripping voltammetry |
title_sort |
measurement of iron chemical speciation in seawater at 4°c: the use of competitive ligand exchange-adsorptive cathodic stripping voltammetry |
publishDate |
2013 |
url |
http://hdl.handle.net/10453/27431 |
long_lat |
ENVELOPE(-59.517,-59.517,-62.500,-62.500) |
geographic |
Southern Ocean Tac |
geographic_facet |
Southern Ocean Tac |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_relation |
Marine Chemistry 10.1016/j.marchem.2012.12.007 Marine Chemistry, 2013, 149 pp. 63 - 73 0304-4203 http://hdl.handle.net/10453/27431 |
_version_ |
1766207333906513920 |