Fluorescence reactions of the dysprosium(III)-tiron-calcium(II) mixed-metal complex

Abstract

A sensitive spectrofluorimetric method for the determination of dysprosium has been developed, based on the formation of a fluorescent mixed-metal complex of dysprosium with Tiron and calcium ion. At a pH between 10.8 and 12.5 the reaction is instantaneous. The system emits the sharp line fluorescence of dysprosium(III)(576 nm) with an excitation wavelength of 321 nm and the fluorescence intensity remains stable for 2 h. Beer's law is obeyed over the range 0.6–6 ng ml^–1 of dysprosium. The stoicheiometric composition of the mixed-metal complex is 1:3:6 (Dy : Ca : Tiron). The method has been applied successfully to a synthetic sample of rare-earth elements.