Show simple item record

dc.contributor.authorAguilar Camaño, David
dc.contributor.authorParat, C.
dc.contributor.authorGalceran i Nogués, Josep
dc.contributor.authorCompanys Ferran, Encarnació
dc.contributor.authorPuy Llorens, Jaume
dc.contributor.authorAuthier, L.
dc.contributor.authorPotin-Gautier, M.
dc.date.accessioned2015-11-04T09:08:01Z
dc.date.available2015-11-04T09:08:01Z
dc.date.issued2013-01-15
dc.identifier.issn1572-6657
dc.identifier.urihttp://hdl.handle.net/10459.1/48908
dc.description.abstractThe determination of free metal ion concentrations of heavy metals, like Zn2+ or Cd2+, with AGNES (Absence of Gradients and Nernstian Equilibrium Stripping) requires an adequate selection of parameters such as deposition potential (linked to the gain, [M-0]/[M2+]) and deposition time. In systems with low ionic strength, the peak potential of the Differential Pulse Polarogram (DPP) measured with low supporting electrolyte is not always suitable for the computation of the gain with existing expressions. The application of AGNES with a constant potential (regardless of the ionic strength) provides a direct measurement of the metal ion activity. When working with low ionic strength solutions, the selection of appropriate instrumentation is important to avoid changes in liquid junction potentials or leakages from the employed electrodes. The deposition times (for a given gain) have not been found to be greatly affected by the probed ionic strengths when working with just metal. A new strategy for the practical implementation of AGNES to measure free metal ion concentrations in samples with low KNO3 or Ca(NO3)(2) concentrations consists in the computation of the deposition potential (to reach a certain gain) from the DPP peak potential at a sufficiently high ionic strength using a new expression. A speciation experiment with Zn2+ and glycine at pHs between 4 and 7.5, where [KNO3] = 0.001 M, shows that this methodology works well and also proves that it is possible to perform AGNES in systems with very low ionic strength. (C) 2012 Elsevier B.V. All rights reserved.
dc.format.mimetypeapplication/pdf
dc.language.isoeng
dc.publisherElsevier
dc.relation.isformatofVersió postprint del document publicat a: https://doi.org/10.1016/j.jelechem.2012.11.010
dc.relation.ispartofJournal of Electroanalytical Chemistry, 2013, vol. 689, num. 15, p. 276-283
dc.rights(c) Elsevier, 2013
dc.subjectLow ionic strength
dc.subjectElectrolyte
dc.subjectFree metal concentration
dc.subjectAGNES (Absence of Gradients and Nernstian Equilibrium Stripping)
dc.subject.classificationSolucions electrolítiques
dc.subject.classificationElectroquímica
dc.subject.otherElectrolyte solutions
dc.subject.otherElectrochemistry
dc.titleDetermination of free metal ion concentrations with AGNES in low ionic strength media
dc.typeinfo:eu-repo/semantics/article
dc.date.updated2015-11-04T09:08:01Z
dc.identifier.idgrec019735
dc.type.versioninfo:eu-repo/semantics/acceptedVersion
dc.rights.accessRightsinfo:eu-repo/semantics/openAccess
dc.identifier.doihttps://doi.org/10.1016/j.jelechem.2012.11.010


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record