Quantification of iron in seawater at the low picomolar range based on the optimization of the bromate-ammonia-dihydroxynaphtalene system by catalytic adsorptive cathodic stripping voltammetry
[eng] A new analytical protocol for the challenging analysis of total dissolved iron at the low picomolar level in oceanic waters suitable for onboard analysis is presented. The method is based on the revision of the adsorptive properties of the iron/2,3-dihydroxynaphthalene (Fe/DHN) complexes on th...
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ftunillesbalears:oai:dspace.uib.es:11201/147668 2023-05-15T18:25:48+02:00 Quantification of iron in seawater at the low picomolar range based on the optimization of the bromate-ammonia-dihydroxynaphtalene system by catalytic adsorptive cathodic stripping voltammetry Laglera Baquer, Luis Miguel Santos Echeandía, Juan Caprara, Salvatore Monticelli, Damiano application/pdf http://hdl.handle.net/11201/147668 unknown Versió postprint del document publicat a: Analytical Chemistry, 2013, vol. 85, num. 4, p. 2486-2492 http://hdl.handle.net/11201/147668 info:eu-repo/semantics/embargoedAccess 54 - Química 54 - Chemistry. Crystallography. Mineralogy info:eu-repo/semantics/article info:eu-repo/semantics/acceptedVersion ftunillesbalears 2021-06-25T17:58:10Z [eng] A new analytical protocol for the challenging analysis of total dissolved iron at the low picomolar level in oceanic waters suitable for onboard analysis is presented. The method is based on the revision of the adsorptive properties of the iron/2,3-dihydroxynaphthalene (Fe/DHN) complexes on the hanging mercury drop electrode with catalytic enhancement by bromate ions. Although it was based on a previously proposed reagent combination, we show here that the addition of an acidification/alkalinization step is essential in order to cancel any organic complexation, and that an extra increment of the pH to 8.6−8.8 leads to the definition of a preconcentration-free procedure with the lowest detection limit described up to now. For total dissolved iron analysis, samples were acidified to pH 2.0 in the presence of 30 μM DHN and left to equilibrate overnight. A 10 mL sample was subsequently buffered to a pH of ∼8.7 in the presence of 20 mM bromate: a 60 s deposition at 0 V led to a sensitivity of 34 nA nM−1 min−1, a 4-fold improvement over previous methods, that translated in a limit of detection of 5 pM (2−20 fold improvement). Several tests proved that a nonreversible reaction in the time scale of the analysis, triggered by the acidification/alkalinization step, was behind the signal magnification. The new method was validated onboard via the analysis of reference material and via intercalibration against flow injection analysis-chemiluminescence on Southern Ocean surface samples. Article in Journal/Newspaper Southern Ocean UIB Repositori (University of the Balearic Islands) Southern Ocean |
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UIB Repositori (University of the Balearic Islands) |
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ftunillesbalears |
language |
unknown |
topic |
54 - Química 54 - Chemistry. Crystallography. Mineralogy |
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54 - Química 54 - Chemistry. Crystallography. Mineralogy Laglera Baquer, Luis Miguel Santos Echeandía, Juan Caprara, Salvatore Monticelli, Damiano Quantification of iron in seawater at the low picomolar range based on the optimization of the bromate-ammonia-dihydroxynaphtalene system by catalytic adsorptive cathodic stripping voltammetry |
topic_facet |
54 - Química 54 - Chemistry. Crystallography. Mineralogy |
description |
[eng] A new analytical protocol for the challenging analysis of total dissolved iron at the low picomolar level in oceanic waters suitable for onboard analysis is presented. The method is based on the revision of the adsorptive properties of the iron/2,3-dihydroxynaphthalene (Fe/DHN) complexes on the hanging mercury drop electrode with catalytic enhancement by bromate ions. Although it was based on a previously proposed reagent combination, we show here that the addition of an acidification/alkalinization step is essential in order to cancel any organic complexation, and that an extra increment of the pH to 8.6−8.8 leads to the definition of a preconcentration-free procedure with the lowest detection limit described up to now. For total dissolved iron analysis, samples were acidified to pH 2.0 in the presence of 30 μM DHN and left to equilibrate overnight. A 10 mL sample was subsequently buffered to a pH of ∼8.7 in the presence of 20 mM bromate: a 60 s deposition at 0 V led to a sensitivity of 34 nA nM−1 min−1, a 4-fold improvement over previous methods, that translated in a limit of detection of 5 pM (2−20 fold improvement). Several tests proved that a nonreversible reaction in the time scale of the analysis, triggered by the acidification/alkalinization step, was behind the signal magnification. The new method was validated onboard via the analysis of reference material and via intercalibration against flow injection analysis-chemiluminescence on Southern Ocean surface samples. |
format |
Article in Journal/Newspaper |
author |
Laglera Baquer, Luis Miguel Santos Echeandía, Juan Caprara, Salvatore Monticelli, Damiano |
author_facet |
Laglera Baquer, Luis Miguel Santos Echeandía, Juan Caprara, Salvatore Monticelli, Damiano |
author_sort |
Laglera Baquer, Luis Miguel |
title |
Quantification of iron in seawater at the low picomolar range based on the optimization of the bromate-ammonia-dihydroxynaphtalene system by catalytic adsorptive cathodic stripping voltammetry |
title_short |
Quantification of iron in seawater at the low picomolar range based on the optimization of the bromate-ammonia-dihydroxynaphtalene system by catalytic adsorptive cathodic stripping voltammetry |
title_full |
Quantification of iron in seawater at the low picomolar range based on the optimization of the bromate-ammonia-dihydroxynaphtalene system by catalytic adsorptive cathodic stripping voltammetry |
title_fullStr |
Quantification of iron in seawater at the low picomolar range based on the optimization of the bromate-ammonia-dihydroxynaphtalene system by catalytic adsorptive cathodic stripping voltammetry |
title_full_unstemmed |
Quantification of iron in seawater at the low picomolar range based on the optimization of the bromate-ammonia-dihydroxynaphtalene system by catalytic adsorptive cathodic stripping voltammetry |
title_sort |
quantification of iron in seawater at the low picomolar range based on the optimization of the bromate-ammonia-dihydroxynaphtalene system by catalytic adsorptive cathodic stripping voltammetry |
url |
http://hdl.handle.net/11201/147668 |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_relation |
Versió postprint del document publicat a: Analytical Chemistry, 2013, vol. 85, num. 4, p. 2486-2492 http://hdl.handle.net/11201/147668 |
op_rights |
info:eu-repo/semantics/embargoedAccess |
_version_ |
1766207466962419712 |