Theoretical aspects of dynamic metal speciation with electrochemical techniques

Puy, Jaume; Galceran, Josep

doi:10.1016/j.coelec.2017.01.001

Cited by 11 publications

(11 citation statements)

References 68 publications

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“…Here ξ j is the lability degree (between 0, for inert complexes, and 1, for fully labile complexes) for each metal complex pool ( j = in or org) in the fast or classic DGT (superscripts f or c). The lability degree quantifies the contribution of a given complex (or ensemble of complexes) to the flux received by a microorganism or a sensor in comparison with the maximum possible contribution of this complex if it was fully labile 43 .…”

Section: Discussionmentioning

confidence: 99%

In situ measurements of micronutrient dynamics in open seawater show that complex dissociation rates may limit diatom growth

Baeyens

Gao

Davison

et al. 2018

Sci Rep

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In this first in situ study of the dynamic availability of phytoplankton micronutrients, a SeaExplorer glider was combined with Diffusive Gradients in Thin Films and deployed in the Mediterranean Sea. On the basis of their labile metal complex pools, we discovered that Fe and Co can be potentially limiting and Cu co-limiting to diatom growth, contrary to the generally accepted view that phosphorus (phosphate) is the growth limiting element in the Mediterranean Sea. For flagellates and picoplankton, phosphorus remains the main element limiting growth. Our in situ measurements showed that organic complexes of Fe and Cu (>98% of total dissolved concentration), dissociate slower than inorganic complexes of Co, Cd and Ni (>99% of total dissolved concentration being free ions and inorganic complexes). This strengthens the potential growth limiting effect of Fe and Cu versus phosphate, which is present as a free ion and, thus, directly available for plankton.

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Section: Discussionmentioning

confidence: 99%

In situ measurements of micronutrient dynamics in open seawater show that complex dissociation rates may limit diatom growth

Baeyens

Gao

Davison

et al. 2018

Sci Rep

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“…c DGT can also be interpreted in terms of the real species present in the sample, as indicated in Equation (3) below. The lability degree, ξ j , quantifies the contribution of a given complex M j L to the actual flux received by the DGT in comparison with the maximum possible flux of this complex if it was fully labile (local equilibrium fulfilled all throughout the diffusion domain or, equivalently, infinitely large dissociation rate constant; Galceran et al, 2001;Puy and Galceran, 2017). ξ ranges between 0, for inert complexes, to 1, for fully labile complexes.…”

Section: Diffusive Gradient In Thin-films Techniquementioning

confidence: 99%

Speciation of Inorganic Compounds in Aquatic Systems Using Diffusive Gradients in Thin-Films: A Review

et al. 2021

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The speciation of trace metals in an aquatic system involves the determination of free ions, complexes (labile and non-labile), colloids, and the total dissolved concentration. In this paper, we review the integrated assessment of free ions and labile metal complexes using Diffusive Gradients in Thin-films (DGT), a dynamic speciation technique. The device consists of a diffusive hydrogel layer made of polyacrylamide, backed by a layer of resin (usually Chelex-100) for all trace metals except for Hg. The best results for Hg speciation are obtained with agarose as hydrogel and a thiol-based resin. The diffusive domain controls the diffusion flux of the metal ions and complexes to the resin, which strongly binds all free ions. By using DGT devices with different thicknesses of the diffusive or resin gels and exploiting expressions derived from kinetic models, one can determine the labile concentrations, mobilities, and labilities of different species of an element in an aquatic system. This procedure has been applied to the determination of the organic pool of trace metals in freshwaters or to the characterization of organic and inorganic complexes in sea waters. The concentrations that are obtained represent time-weighted averages (TWA) over the deployment period.

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“…Short pulses that prevent the fulfilment of steady-state conditions in the accumulation are also studied. In many natural systems, metal speciation is dominated by the formation of complexes that can exhibit different lability degrees [24][25][26][27] i. e., metal availability is infuenced by the kinetics of the complex dissociation [28]. The last section is devoted to develop an interpretative framework to relate DGT concentrations with parameters of actual chemical species such as concentrations, diffusion coefficients and lability degrees.…”

Section: Introductionmentioning

confidence: 99%

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

Altier

Jiménez-Piedrahita

Uribe

et al. 2019

Analytica Chimica Acta

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Theoretical aspects of dynamic metal speciation with electrochemical techniques

Abstract: Està subjecte a una llicència de Reconeixement-NoComercial-SenseObraDerivada 3.0 de Creative Commons

Cited by 11 publications

References 68 publications

In situ measurements of micronutrient dynamics in open seawater show that complex dissociation rates may limit diatom growth

In situ measurements of micronutrient dynamics in open seawater show that complex dissociation rates may limit diatom growth

Speciation of Inorganic Compounds in Aquatic Systems Using Diffusive Gradients in Thin-Films: A Review

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

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