Spectrofluorimetric determination of titanium,zirconium and hafnium and their binary mixtures with biacetylmonoxime nicotinylhydrazone

The synthesis, characteristics and analytical applications of biacetylmonoxime nicotinylhydrazone are described. This compound forms fluorescent complexes with titanium(IV) (λ_ex = 430, λ_em = 540 nm), zirconium (λ_ex = 415 nm, λ_em = 505 nm) and hafnium (λ_ex = 400, λ_em = 500 nm) in an acidic medium. Titanium forms a 1:2 metal:ligand complex, whereas zirconium and hafnium form 1:2:1 metal:ligand:sulphate ternary complexes. Highly selective spectrofluorimetric methods for titanium (20–100 ng ml^?1), zirconium and hafnium (5–100 ng ml^?1) are proposed, and procedures for the analysis of binary mixtures of these ions are described.