Luminescence studies of Europium (III) - D-glucosamine complexes in water

LUMINESCENCE STUDIES OF EUROPIUM(III) - D-GLUCOSAMINE COMPLEXES IN WATER by Triny Trinh Pham Lanthanide complexation interactions measured by luminescence have become interesting topic in recent years. Europium is a rare earth metal and the Eu(III) ion is a hard acid; when Eu(III) and a monosaccharide ligand are present, a complex may be formed. The goal is to determine the equilibrium constant KEuL between the europium ion and a D-glucosamine ligand. At 25oC and pH ~ 7.40, a physiologically important pH, adding D-glucosamine enhanced the luminescence of 0.0025 M Eu(III). As the concentration of ligand increased, the emission intensity was also increased. The measurement of a hypersensitive peak at 614 nm indicated a complex reaction at pH ~ 7.40. The equilibrium constant of KEuL was found to be 29.24. Based on the FTIR and laser experiments, the results confirmed that D-glucosamine attached to the europium ion (Eu3+) at pH ~ 7.40; there was no evidence that hydrolyzed Eu(III) was present in the complexation