title: Determination of free Zn2+ concentration in synthetic and natural samples with AGNES (Absence of Gradients and Nernstian Equilibrium Stripping) and DMT (Donnan Membrane Technique).
abstract: The determination of free Zn(2+) ion concentration is a key in the study of environmental systems like river water and soils, due to its impact on bioavailability and toxicity. AGNES (Absence of Gradients and Nernstian Equilibrium Stripping) and DMT (Donnan Membrane Technique) are emerging techniques suited for the determination of free heavy metal concentrations, especially in the case of Zn(2+), given that there is no commercial Ion Selective Electrode. In this work, both techniques have been applied to synthetic samples (containing Zn and NTA) and natural samples (Rhine river water and soils), showing good agreement. pH fluctuations in DMT and N(2)/CO(2) purging system used in AGNES did not affect considerably the measurements done in Rhine river water and soil samples. Results of DMT in situ of Rhine river water are comparable to those of AGNES in the lab. The comparison of this work provides a cross-validation for both techniques.
authors.affiliation: Departament de Química, Universitat de Lleida, Rovira Roure 191, 25198 Lleida, Spain.
authors.forename: Diana
authors.initials: D
authors.lastname: Chito
authors.forename: Liping
authors.initials: L
authors.lastname: Weng
authors.forename: Josep
authors.initials: J
authors.lastname: Galceran
authors.forename: Encarnació
authors.initials: E
authors.lastname: Companys
authors.forename: Jaume
authors.initials: J
authors.lastname: Puy
authors.forename: Willem H
authors.initials: WH
authors.lastname: van Riemsdijk
authors.forename: Herman P
authors.initials: HP
authors.lastname: van Leeuwen
mesh_terms: D002411:Cation Exchange Resins; D004784:Environmental Monitoring / Q000295:instrumentation / Q000379:methods*; D004867:Equipment Design; D008567:Membranes, Artificial; D008962:Models, Theoretical; D009426:Netherlands; D045483:Rivers / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D015032:Zinc / Q000032:analysis*
chemical_list: D002411:Cation Exchange Resins; D008567:Membranes, Artificial; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; D015032:Zinc