Analysis of twenty five impurities in uranium matrix by ICP-MS with iron measurement optimized by using reaction collision cell, cold plasma or medium resolution.

An analytical procedure was developed to determine the concentration of 25 impurities (Li, Be, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, Ag, Cd, In, Sm, Eu, Gd, Dy, W, Pb, Bi and Th) in a uranium matrix using the quadrupole inductively coupled plasma mass spectrometry (Q-ICP-MS). The dissolution of U(3)O(8) powder was made with a mixture of hydrochloric acid and nitric acid. Then, a selective separation of uranium using the UTEVA column was used before measurement by Q-ICP-MS. The procedure developed was verified using the Certified Reference Material "Morille". The analytical results agree well except for 5 elements where values are underestimated (Li, Be, In, Pb and Bi). Among the list of impurities, iron was particularly investigated because it is well known that this element possesses a polyatomic interference that increases the detection limit. A comparison between iron detection limits obtained with different methods was performed. Iron polyatomic interference was at least reduced, or at best entirely resolved in some cases, by using the cold plasma or the collision/reaction cell with several gases (He, NH(3) and CH(4)). High-resolution ICP-MS was used to compare the results obtained. A detection limit as low as 8 ng L(-1) was achieved.

Uranium speciation in drinking water from drilled wells in southern Finland and its potential links to health effects.

Exceptionally high concentrations of natural uranium have been found in drinking water originating from drilled wells in Southern Finland. However, no clear clinical symptoms have been observed among the exposed population. Hence a question arose as to whether uranium speciation could be one reason for the lack of significant adverse health effects. Uranium species were determined using time-resolved laser-induced fluorescence spectroscopy. We performed multi-element chemical analyses in these water samples, and predictive calculations were carried out using up-to-date thermodynamic data. The results indicated good agreement between measurements and modeling. The low toxicity of Finnish bedrockwater may be due to the predominance of two calcium-dependent species, Ca2UO2(CO3)3(aq) and CaUO2(CO3)3(2-), whose nontoxicity for cells has been described previously. This interdisciplinary study describes chemical speciation of drinking water with elevated uranium concentrations and the potential consequence on health. From these results, it appears that modeling could be used for a better understanding of uranium toxicity of drinking water in the event of contamination.

Analysis by laser-induced breakdown spectroscopy of complex solids, liquids, and powders with an echelle spectrometer.

One of the most promising approaches to laser-induced breakdown spectroscopy (LIBS) experiments involves the use of an echelle spectrometer coupled with an intensified CCD. Even if drawbacks remain with its use, the echelle spectrometer facilitates a multielemental analysis that is more rapid than can be obtained with the more-conventional Czerny-Turner spectrometer and, moreover, does not sacrifice reliability. Quantitative results obtained with such apparatus for solids, liquids, powders, and gases are described and when possible compared with results from Czerny-Turner spectrometers. Liquid analysis by LIBS with echelle spectrometers has allowed a spectral database to be compiled. Once the qualitative spectra of pure elements in aqueous solutions, are obtained, they can be used for qualitative analysis of unknown samples.

Micro-laser-induced breakdown spectroscopy technique: a powerful method for performing quantitative surface mapping on conductive and nonconductive samples.

Laser-induced breakdown spectroscopy (LIBS) has been applied mainly to bulk analysis of solids, liquids, and gases and less frequently for elemental microanalysis of solid surfaces. A micro-LIBS device devoted to analysis of the distribution of elements on surfaces is described. This device offers rapid access with a 3-microm spatial resolution to the microchemical structures of both conductive and nonconductive samples. Quantitative microchemical results of applications to ceramics are reported. By the use of a time-resolved acquisition spectrum, cerium in a uranium matrix was characterized with a cerium detection limit of 1.14%. Calibration curves obtained with manipulations during 1 year facilitated evaluations of reproducibility and repeatability. A 2% single-shot repeatability with a calibration reproducibility of approximately 7% is reported.