title: Lability criteria in diffusive gradients in thin films.
abstract: The penetration of metal complexes into the resin layer of DGT (diffusive gradients in thin films) devices greatly influences the measured metal accumulation, unless the complexes are either totally inert or perfectly labile. Lability criteria to predict the contribution of complexes in DGT measurements are reported. The key role of the resin thickness is highlighted. For complexes that are partially labile to the DGT measurement, their dissociation inside the resin domain is the main source of metal accumulation. This phenomenon explains the practical independence of the lability degree of a complex in a DGT device with respect to the ligand concentration. Transient DGT regimes, reflecting the times required to replenish the gel and resin domains up to the steady-state profile of the complex, are also examined. Low lability complexes (lability degree between 0.1 and 0.2) exhibit the longest transient regimes and therefore require longer deployment times to ensure accurate DGT measurements.
authors.affiliation: Departament de Química, Universitat de Lleida, Rovira Roure 191, 25198, Lleida, Spain. jpuy@quimica.udl.es
authors.forename: Jaume
authors.initials: J
authors.lastname: Puy
authors.forename: Ramiro
authors.initials: R
authors.lastname: Uribe
authors.forename: Sandrine
authors.initials: S
authors.lastname: Mongin
authors.forename: Josep
authors.initials: J
authors.lastname: Galceran
authors.forename: Joan
authors.initials: J
authors.lastname: Cecília
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Levy
authors.forename: Hao
authors.initials: H
authors.lastname: Zhang
authors.forename: William
authors.initials: W
authors.lastname: Davison