title: Parafac decomposition of three-way kinetic-spectrophotometric spectral matrices corresponding to mixtures of heavy metal ions.
abstract: Binary and ternary mixtures of some of the following heavy metal ions Zn(II), Ni(II), Pb(II), Co(II) and Cd(II) were analyzed by a ligand substitution kinetic method. Three-way data matrices were generated by acquisition of UV-Vis spectra (332-580 nm) as a function of the time of a substitution reaction observed between the complex of the heavy metal ions with the non selective metallochromic indicator 4-(2-pyridylazo) resorcinol (PAR) and EDTA, and of different relative concentration of the metal ions (1-6 mM). The PARAFAC trilinear model, without restrictions, was used in the data analysis. A full decomposition of the data matrices was obtained (spectra, concentration and time profiles). It was shown that ligand substitution kinetic methods coupled to three-way chemometric analytical methods can be used for the development of robust sensors for the analysis of binary [Zn(II)+Ni(II), Pb(II)+Cd(II), Zn(II)+Pb(II)] or ternary [Zn(II)+Pb(II)+Co(II)] mixtures of metal ions in the micromolar concentration range.
authors.affiliation: LAQUIPAI, Chemistry Department, Faculdade de Ciências, R. Campo Alegre 687, Porto, Portugal. jcsilva@fc.up.pt
authors.forename: J C
authors.initials: JC
authors.lastname: Esteves da Silva
authors.forename: C J
authors.initials: CJ
authors.lastname: Oliveira