The relevance of ligand exchange kinetics in the measurement of iron speciation by CLE-AdCSV in seawater

Show simple item record Laglera Baquer, Luis Miguel Filella, Montserrat 2018-09-21T12:33:26Z
dc.description.abstract [eng] CLE-AdCSV (competitive ligand exchange-adsorptive cathodic stripping voltammetry) has proved to be a decisive technique in recognising the key role that organic matter plays in modulating the biogeochemical cycle of iron in aquatic ecosystems. As themethod requires equilibriumamong all the constituents of the solution before measurements are taken, accurate knowledge of the kinetics of the undergoing ligand exchange is essential. The kinetics of the process has beenmost frequently described in terms of a dissociative (or Eigen-Wilkins) mechanism, with some authors even claiming that, under such approach, iron complexes would dissociate during CLE so slowly that the method would be invalidated. The complexity of the processes largely exceeding the simple mechanistic description of the Eigen-Wilkins mechanism is discussed on the basis of a broad overview of possible reaction routes. Evidence of the role of matrix components of natural waters is presented and the impossibility of exporting kinetic constants to systems characterised by different molecular mechanics, mostly ignored in previous studies, is highlighted. Experimental evidence obtained fromvarious methodological approaches allows inferring the range of CLE equilibration times to be applied in CLE-AdCSVmeasurements and further proves that the Eigen-Wilkins mechanism is just one of the many reaction routes applicable in natural waters. Studying iron CLE mechanisms for proposed competing ligands before designing any experiment using CLE-AdCSV is recommended.
dc.format application/pdf
dc.relation.isformatof Versió postprint del document publicat a:
dc.relation.ispartof Marine Chemistry, 2015, vol. 173, p. 100-113
dc.rights (c) Elsevier B.V., 2015
dc.subject.classification 54 - Química
dc.subject.other 54 - Chemistry. Crystallography. Mineralogy
dc.title The relevance of ligand exchange kinetics in the measurement of iron speciation by CLE-AdCSV in seawater
dc.type info:eu-repo/semantics/article
dc.type info:eu-repo/semantics/acceptedVersion 2018-09-21T12:33:26Z info:eu-repo/date/embargoEnd/2075-01-01
dc.embargo 2075-01-01
dc.rights.accessRights info:eu-repo/semantics/embargoedAccess

Files in this item

This item appears in the following Collection(s)

Show simple item record

Search Repository

Advanced Search


My Account