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dc.contributor.authorQuattrini, Federico
dc.contributor.authorGalceran i Nogués, Josep
dc.contributor.authorRey Castro, Carlos
dc.contributor.authorPuy Llorens, Jaume
dc.contributor.authorFortin, Claude
dc.date.accessioned2019-10-10T13:27:25Z
dc.date.available2019-10-10T13:27:25Z
dc.date.issued2019
dc.identifier.issn1448-2517
dc.identifier.urihttp://hdl.handle.net/10459.1/66765
dc.description.abstractThe dynamic ion exchange technique (DIET) is proposed to provide speciation information, which can be used to establish links with metal bioavailability in natural waters. The experimental setup consists of a few milligrams of a sulfonic acid type ion exchange resin packed in a plastic microcolumn that is coupled to a peristaltic pump for a sample to interact with the resin which is subsequently eluted. The evolution of both the accumulated number of moles in the resin and the concentration of the effluent can provide information on the dissociation of different metal-ligand complexes when compared with the transport properties. This information can be converted into the lability degree of a given complex or the DIET concentration c(DIET), which accounts for the labile fraction contributing to the metal accumulation by the resin column at the operation conditions. c(DIET) can be extended to columns containing chelating resins (such as those with Chelex) or to chromatography. A comprehensive modelling of the involved phenomena (such as diffusion, advection, reaction kinetics and electrostatic partitioning) leads to the quantitative interpretation of the accumulation time series (accumulation curves) or effluent evolution (breakthrough curves). Particularly simple analytical expressions can be used for short exposure times, when a (quasi) steady-state is attained. These models have been checked against the results from complexes of Cu and Ni with ligands, such as ethylenediamine, and ethylenediaminetetraacetic, iminodiacetic, glutamic, salicylic, malonic and malic acids, which yield complexes with contrasting charges. Caution is advised when estimating the free metal fraction from DIET measurements, as c(DIET) and the free metal concentration can be considered to be equal only in the case of extremely inert complexes.
dc.description.sponsorshipThe authors gratefully acknowledge support for this research from the Spanish Ministry MINECO (Project CTM2016–78798).
dc.format.mimetypeapplication/pdf
dc.language.isoeng
dc.publisherCSIRO Publishing
dc.relationMINECO/PN2013-2016/CTM2016-78798
dc.relation.isformatofVersió postprint del document publicat a: https://doi.org/10.1071/en18202
dc.relation.ispartofEnvironmental Chemistry, 2019, vol. 16, num. 3, p. 151-164
dc.rights(c) CSIRO, 2019
dc.subjectAvailability
dc.subjectIon exchange columns
dc.subjectTrace metal speciation
dc.titleAssessment of labilities of metal complexes with the dynamic ion exchange technique
dc.typeinfo:eu-repo/semantics/article
dc.date.updated2019-10-10T13:27:25Z
dc.identifier.idgrec028838
dc.type.versioninfo:eu-repo/semantics/acceptedVersion
dc.rights.accessRightsinfo:eu-repo/semantics/openAccess
dc.identifier.doihttps://doi.org/10.1071/en18202


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