Aqueous Solutions of Uranium(VI) as Studied by Time-Resolved Emission Spectroscopy: A Round-Robin Test

Abstract

Results are presented of an interlaboratory round-robin study of the application of timeResolved Emission Spectroscopy (TRES) to the speciation of uranium(VI) in aqueous media. This involved 13 independent laboratories, using various instrumental adevices and data 2 analysis methods. In some cases, experimental data from a laboratory were analysed using different softwares. Samples were prepared based on appropriate speciation diagrams and in general were found to be chemically stable for at least six months. Four different types of aqueous uranyl solutions were studied: (i) acidic medium where UO 2 2+ aq is the single emitting species, (ii) uranyl in the presence of fluoride ions, (iii) uranyl in the presence of sulfate ions, and (iv) uranyl in aqueous solutions under various pH conditions, promoting hydrolysed species. Results between the laboratories are compared in terms of number of decay components, luminescence lifetimes and spectral band positions. The potentials and limitations of TRES in uranyl analysis and speciation in aqueous solutions are discussed.

Identification of the uranium speciation in an underground acid mine drainage environment

“…In a fingerprinting procedure the TRLFS spectra obtained are then identified with the help of previously recorded reference substances. At an excitation wavelength of 266 nm the photoluminescence quantum yield for uranium(VI) is high and the respective uranium(VI) photoluminescence is detected in the range of 470-600 nm (Billard et al, 2003).…”

“…Elemental uranium does not emit photoluminescence , whereas U(IV) (Kirishima et al, 2003(Kirishima et al, , 2004, U(V) (Großmann et al, 2007(Großmann et al, , 2009Steudtner et al, 2006), and, in particular, U(VI) emit characteristic photoluminescence signals and are thus detectable. Aqueous complexes of hexavalent uranium have been well investigated (Billard et al, 2003;Brendler et al, 1996;Wang et al, 2004) as also have solid uranium(VI) phases (Amayri et al, 2004a,b;Arnold and Baumann, 2009) and uranyl(VI) species adsorbed on mineral surfaces (Baumann et al, 2005;Arnold et al, 2006;Křepelová et al, 2007). The detection limit for aqueous uranium is currently 0.2 lg L À1 (Bernhard and Geipel, 2007).…”

EuIII Luminescence in a Hygroscopic Ionic Liquid: Effect of Water and Evidence for a Complexation Process

“…Therefore, in the following, the discussion of the decay behavior only corresponds to lifetimes ascribable to Eu III . The importance of the decay behavior (either mono-or multiexponential) has been stressed in other papers [22,26] and the quality of the fits was assessed both by the usual χ 2 test and the shape of the residuals (experimental minus calculated values). The error in the lifetime values was of the order of Ϯ3%.…”

Luminescence Analysis of Actinides: Instrumentation, Applications, Quantification, Future Trends, and Quality Assurance

“…In the case of multiple decaying spectra, they were requested to ascribe a given lifetime to a given group of emission peaks, if possible. The detailed analysis of this round-robin test has been published [12], so we will just summarize the main results.…”