Fluorescence determination of europium with pyridine-2,4,6-tricarboxylic acid

Europium can form a stable chelate with pyridine-2,4,6-tricarboxylic acid (PTA) with a ratio of 1:1 in aqueous. The system, having the maximum excitation and emission wavelengths at 311.0 nm and 616.3 nm, separately, shows a con-stant fluorescence intensity in the pH range of 11.0-12.0. The method has high selectivity and sensitivity as well as low ef-fect from foreign ions. The optimum determinate conditions were obtained. The fluorescence intensity is a linear function of Eu3+ concentration in the range of 0.0029-1.5200 μg?mL?1 and the limit of detection is 2.90 ng?mL?1.