Spectrofluorimetric determination of hafnium and zirconium with 3,7-dihydroxyflavone

Abstract

The absorptive and fluorescent characteristics of the hafnium and zirconium complexes of 3-hydroxyflavone and its 12 hydroxy and methoxy derivatives have been studied. The fluorescence of the 1 : 1 hafnium-3,7-dihydroxyflavone complex (λ_ex. 397 nm, λ_em. 465 nm) in 3 M hydrochloric acid has been used to determine 2–40 ng ml^–1 of hafnium. The fluorescence of the 1 : 1 zirconium-3,7-dihydroxyflavone complex (λ_ex. 395 nm, λ_em. 465 nm) at pH 2.0 in 0.02 M sulphate solution has been used to determine 2–40 ng ml^–1 of zirconium. These methods are very sensitive and can be used for the simultaneous determination of hafnium and zirconium with an error of about 5%.