title: Simultaneous spectrofluorimetric determination of the rare earths with calcein.
abstract: The reactivity of the fluorescent reagent calcein with the trivalent cations of the rare earths has been spectrofluorimetrically studied in aqueous solution. Optimum excitation and emission wavelengths were 492-497 and 519-522 nm, respectively. Optimum pH was in the range 6.0-9.2. The stoichiometry of the complexes was 1:1. A direct, rapid and sensitive method for the determination of rare earth mixtures has been proposed with a detection limit of 4.49x10(-8) M and a coefficient of variation of 0.82%.
authors.affiliation: Unity of Analytical Chemistry, Faculty of Chemistry, University of the Basque Country, 20009 Donostia/San Sebastián, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Berregi
authors.forename: J
authors.initials: J
authors.lastname: Senén Durand
authors.forename: J
authors.initials: J
authors.lastname: Alfonso Casado