The spectrofluorimetric determination of europium and terbium

Abstract

The fluorescent properties of the tris chelates of europium and various β-diketones have been examined. Fluorinated ligands give better sensitivity than unfluorinated ligands, but the best sensitivity is found with 2-thenoyltrifluoroacetone in dimethylformamide. A rapid method for the determination of 10^–7 to 10^–8M europium(III) is discussed. Both europium and terbium can be readily determined in the 10^–2 to 10^–3M range by measurement of the fluorescence of the complexes formed with dimethylformamide alone.