Merck
  • Inicio
  • Resultados de la búsqueda
  • Evaluation of diffusive gradients in thin films technique (DGT) for measuring Al, Cd, Co, Cu, Mn, Ni, and Zn in Amazonian rivers.

Evaluation of diffusive gradients in thin films technique (DGT) for measuring Al, Cd, Co, Cu, Mn, Ni, and Zn in Amazonian rivers.

Environmental monitoring and assessment (2013-09-21)
Lauren Nozomi Marques Yabuki, Camila Destro Colaço, Amauri Antonio Menegário, Roberto Naves Domingos, Chang Hung Kiang, Domitila Pascoaloto
RESUMEN

Studies concerning the lability and bioavailability of trace metals have played a prominent role in the search for contamination of water resources. This work describes the first application yet of the diffusive gradients in thin films technique (DGT) to the determination of the fraction of free plus labile metals in waters from the Amazon Basin. Due to the complexity of the use of DGT for samples with low ionic strength and high organic matter content (characteristic of Amazonian rivers), a new analytical procedure was developed. The method is based on the determinations of apparent diffusion coefficients (Dap) in the laboratory, by performing deployments in samples collected in the corresponding sites of study. The Dap thereby determined is then used for in situ measurements. The suitability of the proposed approach for determination of labile Al, Cd, Co, Cu, Mn, Ni, and Zn in the Amazon River and Rio Negro (English: Black River) was evaluated. Except for Co, Mn (in a deployment at Rio Negro), Ni and Zn (in a deployment at Amazon River), labile in situ measurements were lower or similar to dissolved concentrations, indicating suitability of the proposed approach.

MATERIALES
Referencia del producto
Marca
Descripción del producto

Sigma-Aldrich
Nickel, sputtering target, diam. × thickness 2.00 in. × 0.25 in., 99.95% trace metals basis
Sigma-Aldrich
Cadmium, powder, −100 mesh, 99.5% trace metals basis
Sigma-Aldrich
Raney®-Nickel, W.R. Grace and Co. Raney® 2400, slurry, in H2O, active catalyst
Sigma-Aldrich
Raney®-Nickel, W.R. Grace and Co. Raney® 3202, slurry, in H2O, active catalyst
Sigma-Aldrich
Cadmium, rod, diam. 4.0 mm, 99.999% trace metals basis
Sigma-Aldrich
Raney®-Nickel, W.R. Grace and Co. Raney® 4200, slurry, in H2O, active catalyst
Sigma-Aldrich
Cadmium, granular, ≥99%, 5-20 mesh
Sigma-Aldrich
Nickel, powder, <150 μm, 99.99% trace metals basis
Sigma-Aldrich
Cadmium, wire, diam. 1.0 mm, 99.999% trace metals basis
Sigma-Aldrich
Cadmium, shot, 3 mm, 99.999% trace metals basis
Sigma-Aldrich
Raney®-Nickel, W.R. Grace and Co. Raney® 2800, slurry, in H2O, active catalyst
Sigma-Aldrich
Nickel, foil, thickness 0.25 mm, 99.995% trace metals basis
Sigma-Aldrich
Nickel, wire, diam. 0.5 mm, ≥99.99% trace metals basis
Sigma-Aldrich
Nickel, wire, diam. 0.25 mm, ≥99.9%
Sigma-Aldrich
Cadmium, granular, 30-80 mesh, ≥99%
Sigma-Aldrich
Aluminum, foil, thickness 0.25 mm, 99.999% trace metals basis
Sigma-Aldrich
Nickel, foil, thickness 0.125 mm, ≥99.9%
Sigma-Aldrich
Nickel, powder, <1 μm, 99.8% trace metals basis
Sigma-Aldrich
Aluminum, foil, thickness 0.13 mm, ≥99.99% trace metals basis
Sigma-Aldrich
Aluminum, foil, thickness 0.45-0.55 mm, 99.999% trace metals basis
Sigma-Aldrich
Aluminum, pellets, 3-12 mm, 99.99% trace metals basis
Sigma-Aldrich
Aluminum, foil, thickness 1.0 mm, 99.999% trace metals basis
Aluminum, IRMM®, certified reference material, 0.1 mm foil
Sigma-Aldrich
Cobalt, Carbon coated magnetic, nanopowder, <50 nm particle size (TEM), ≥99%
Sigma-Aldrich
Aluminum, foil, thickness 8 μm, 99% trace metals basis
Sigma-Aldrich
Nickel, nanopowder, <100 nm avg. part. size, ≥99% trace metals basis
Sigma-Aldrich
Aluminum, sputtering target, diam. × thickness 3.00 in. × 0.125 in., 99.9995% trace metals basis
Sigma-Aldrich
Cobalt, granular, 99.99% trace metals basis
Sigma-Aldrich
Cobalt, powder, <150 μm, ≥99.9% trace metals basis
Sigma-Aldrich
Cobalt, rod, diam. 5.0 mm, 99.998% trace metals basis