Time weighted average concentrations measured with Diffusive Gradients in Thin films (DGT)

dc.contributor.authorAltier Infantes, Alexandra
dc.contributor.authorJiménez-Piedrahita, Martín
dc.contributor.authorUribe Kaffure, Ramiro
dc.contributor.authorRey Castro, Carlos
dc.contributor.authorGalceran i Nogués, Josep
dc.contributor.authorPuy Llorens, Jaume
dc.date.accessioned2019-10-10T13:45:16Z
dc.date.available2020-07-04T22:21:29Z
dc.date.issued2019-07-04
dc.date.updated2019-10-10T13:45:17Z
dc.description.abstractTime weighted average (TWA) concentrations can improve the assessment of water quality. DGT (Diffusive Gradients in Thin films) devices have been suggested as simple tools to measure TWA metal concentrations, but the connection of TWA with C-DGT has not been rigorously discussed. It is shown here that C-DGT is the average DGT-labile concentration along the deployment, which suggests that it is well suited to correlate with toxicity effects. In terms of real species, C-DGT is a good estimator of the TWA concentration for simple metal solutions (no ligands are present) when the accumulation takes place under perfect sink conditions. Differences between CDGT and the TWA concentration for short pulses (<40 min), when the transient regime becomes relevant, are reported. In the presence of complexes, C-DGT contains the TWA of the product of the labile fraction times the diffusivity of the complex (relative to that of the free metal). This means that C-DGT can underestimate the TWA of the total metal concentration due to the presence of complexes less mobile than the free metal or not fully labile. These findings are illustrated with Cd, Ni, Mg or Ni + nitrilotriacetic acid (NTA) solutions. When only one complex is relevant, as in the Ni + NTA system, a simple correction factor can yield the TWA concentration from C-DGT.
dc.description.sponsorshipThe authors gratefully acknowledge support for this research from the Spanish Ministry MCIU/AEI (Project CTM2016-78798) and FEDER UE (POCTEFA project EFA 183-16 OUTBIOTICS)
dc.format.mimetypeapplication/pdf
dc.identifier.doihttps://doi.org/10.1016/j.aca.2019.01.056
dc.identifier.idgrec028837
dc.identifier.issn0003-2670
dc.identifier.urihttp://hdl.handle.net/10459.1/66766
dc.language.isoeng
dc.publisherElsevier
dc.relationinfo:eu-repo/grantAgreement/MINECO//CTM2016-78798/ES/
dc.relation.isformatofVersió postprint del document publicat a: https://doi.org/10.1016/j.aca.2019.01.056
dc.relation.ispartofAnalytica Chimica Acta, 2019, vol. 1060, p. 114-124
dc.rightscc-by-nc-nd (c) Elsevier, 2019
dc.rights.accessRightsinfo:eu-repo/semantics/openAccess
dc.rights.urihttp://creativecommons.org/licenses/by-nc-nd/3.0/es
dc.subjectPassive sampling
dc.subjectConcentration fluctuation
dc.subjectTime average concentration
dc.subjectLability degree
dc.subjectTransient effects
dc.subjectComplexation
dc.titleTime weighted average concentrations measured with Diffusive Gradients in Thin films (DGT)
dc.typeinfo:eu-repo/semantics/article
dc.type.versioninfo:eu-repo/semantics/acceptedVersion
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