Ultrasensitive determination of europium using microsecond time-resolved spectrofluorimetry

Abstract

4,7-Bis(chlorosulphophenyl)-1,10-phenanthroline-2,9-dicarboxylic acid (BCPDA) is proposed as a simple, highly sensitive and specific reagent for the ultrasensitive determination of Eu³⁺ with microsecond time-resolved spectrofluorimetry. The optimum reaction pH was 9.0 in a glycine buffer. Detection limit for Eu³⁺ was 3 × 10^–13 mol l^–1. No major interferences from other metals were found when the interferent was present in a 500-fold molar excess. Negative interference was observed at high (>1 × 10^–3 mol l^–1) concentrations of Fe³⁺ and Ca²⁺ presumably through the formation of non-fluorescent complexes with BCPDA.