A fluorescence spectroscopic study on the speciation of Cm(III) and Eu(III) in the presence of organic chelates in highly basic solutions
-
Zheming Wang
Summary
The speciation of Eu(III) and Cm(III) was investigated by time resolved laser fluorescence spectroscopy (TRLFS) over a range of base concentrations from 0.01M NaOH to 7.5M NaOH and in the presence of several organic chelates including EDTA, HEDTA, NTA, and oxalate. The results of this work suggest that both Eu(III) and Cm(III) form strong mixed ligand complexes with organic chelates and the hydroxyl groups(s) in dilute NaOH solutions. However, in concentrated NaOH solutions, Eu(III)-/Cm(III)-containing colloidal nanoparticles are the primary cause for the measured Eu(III)/Cm(III) in the aqueous solutions. Therefore, the interpretation of these data solely in terms of the formation of amphoteric hydroxyl species ( e.g. Eu(OH)4-) would appear to be inappropriate. The organic chelating ligands form strong complexes with surface Cm(III)/Eu(III) sites of the colloidal nanoparticles. For Cm(III), such surface complexes show largely red-shifted fluorescence spectra as compared with the aqueous complexes and unusually short fluorescence lifetimes. The decreased fluorescence lifetimes are likely due to the presence of transition metal impurities in the nanoparticle and reduced inter-nuclear distance between neighboring Cm(III) centers.
© 2003 Oldenbourg Wissenschaftsverlag GmbH
Artikel in diesem Heft
- The influence of ozone on ligand-assisted extraction of 239Pu and 241Am from Rocky Flats soil
- Biosorption of americium-241 by Candida sp.
- Uranium speciation in plants
- A fluorescence spectroscopic study on the speciation of Cm(III) and Eu(III) in the presence of organic chelates in highly basic solutions
- Synthesis and characterization of neptunyl(VI) and plutonyl(VI) orthosilicates
- Determination of uranium(IV) hydrolysis constants and solubility product of UO2·xH2O
- A comparision of the extraction of carrier-free 176,177W and 99Mo with that of U, Th, Am, Cm, La, Ce, Tm, Yb, Lu and Hf into Aliquat 336 in toluene from nitric, phosphoric, and sulphuric acid media
- Field study of the migration of 90Sr in a weak loess aquifer
- Standardisation of the prompt gamma activation analysis method
Artikel in diesem Heft
- The influence of ozone on ligand-assisted extraction of 239Pu and 241Am from Rocky Flats soil
- Biosorption of americium-241 by Candida sp.
- Uranium speciation in plants
- A fluorescence spectroscopic study on the speciation of Cm(III) and Eu(III) in the presence of organic chelates in highly basic solutions
- Synthesis and characterization of neptunyl(VI) and plutonyl(VI) orthosilicates
- Determination of uranium(IV) hydrolysis constants and solubility product of UO2·xH2O
- A comparision of the extraction of carrier-free 176,177W and 99Mo with that of U, Th, Am, Cm, La, Ce, Tm, Yb, Lu and Hf into Aliquat 336 in toluene from nitric, phosphoric, and sulphuric acid media
- Field study of the migration of 90Sr in a weak loess aquifer
- Standardisation of the prompt gamma activation analysis method
