title: Chemometric approach to visualize and easily interpret data from sequential extraction procedures applied to sediment samples.
abstract: The aim of this study was to assess metal mobility/availability in coastal surface (oxic) sediment samples from the Bahía Blanca estuary. Particularly, two sequential extraction procedures able to discriminate metals associated to amorphous Fe and Mn oxides and those associated with crystalline oxides of Fe were applied. Sequential procedures differ in the number of steps, type of reagents used, and in the order in which metals associated to organic matter are extracted. The studied metals were Cd, Cr, Cu, Pb, Ni and Zn because of their hazardous potential and relative abundance in the estuary. Tucker4 model with three factors describes appropriately the data sets (explained variance of 64.05%). This model made it possible to visualize and explain the information underlying in the data set. From the multivariate analysis, it was possible to evaluate the metal behaviour and their availability. In this way, Cd and Zn are associated to the more available fractions whereas Ni, Cr, Cu and Pb are mainly associated to the unavailable fractions. On the other hand, Zn and Cu are associated to organic matter fraction. Despite the fact that the two-fractionation schemes are quite different, the results obtained with both schemes are comparable.
authors.affiliation: Instituto de Química del Sur, INQUISUR (UNS-CONICET), Av. Alem 1253, B8000CPB Bahía Blanca, Buenos Aires, Argentina. Electronic address: malvarez@criba.edu.ar.
authors.forename: Mónica B
authors.initials: MB
authors.lastname: Alvarez
authors.affiliation: Marine Chemistry Laboratory, IADO (UNS-CONICET), Florida 8000, B8000FWB, Bahía Blanca, Buenos Aires, Argentina.
authors.forename: Pamela Y
authors.initials: PY
authors.lastname: Quintas
authors.affiliation: Instituto de Química del Sur, INQUISUR (UNS-CONICET), Av. Alem 1253, B8000CPB Bahía Blanca, Buenos Aires, Argentina.
authors.forename: Claudia E
authors.initials: CE
authors.lastname: Domini
authors.affiliation: Instituto de Química del Sur, INQUISUR (UNS-CONICET), Av. Alem 1253, B8000CPB Bahía Blanca, Buenos Aires, Argentina.
authors.forename: Mariano
authors.initials: M
authors.lastname: Garrido
authors.affiliation: Instituto de Química del Sur, INQUISUR (UNS-CONICET), Av. Alem 1253, B8000CPB Bahía Blanca, Buenos Aires, Argentina.
authors.forename: Beatriz S
authors.initials: BS
authors.lastname: Fernández Band
mesh_terms: D001118:Argentina; D005591:Chemical Fractionation; D063366:Estuaries; D019015:Geologic Sediments / Q000737:chemistry*; D019216:Metals, Heavy / Q000737:chemistry*; D008962:Models, Theoretical; D010087:Oxides / Q000737:chemistry
chemical_list: D019216:Metals, Heavy; D010087:Oxides
keywords: Four-way Tucker model; Metal fractionation; Oxide phases; Sediment samples; Sequential extraction procedures