Multi-elemental Nd, Sm, Eu, Gd isotope ratio measurements by stop-flow isotachophoresis coupled to MC-ICPMS.

In this study, a new analytical procedure based on isotachophoresis (ITP) coupled to a multi collector inductively coupled plasma mass spectrometer named Stop-Flow-ITP-MC-ICPMS is developed for exhaustive and high-precision multi-elemental isotopic characterization. We demonstrate that Stop-Flow-ITP makes it possible to stop the analytes migration several times for a duration compatible with the detector configuration changes without losing the separation performance. With this procedure, isotope ratio measurements of four lanthanides of interest for nuclear applications (Nd, Sm, Eu and Gd) were obtained with a reproducibility better than 0.4% in a single analysis with only 20ng of each element. A nebulization interface between ITP and MC-ICPMS composed of a dual inlet spray chamber and a multiple flow stream valve made it possible to perform isotopic reference standard injections for on-line mass bias correction by the sample standard bracketing approach. The flexibility of the Stop-Flow-ITP-MC-ICPMS procedure opens the way to online determination of isotope ratio measurements of multiple analytes present in a sample in a single analysis.

Evaluation of superficially and fully porous particles for HILIC separation of lanthanide-polyaminocarboxylic species and simultaneous coupling to ESIMS and ICPMS.

In this work, amide-bonded columns packed with fully porous particles (FPP) and superficially porous particles (SPP) were evaluated to separate lanthanide-polyaminocarboxylic species by hydrophilic interaction liquid chromatography (HILIC), using two model samples of interest in nuclear and other industrial applications. We assessed the gains achieved by reducing the dimensions of the columns along with the size of the FPPs to sub-2 µm and by using sub-3 µm SPP-packed columns. The FPP-packed Acquity column (100 × 2.1 mm; 1.7 µm) performed better than the SPP-packed Accucore column (150 × 2.1 mm; 2.6 µm), with a separation that was two times more efficient and three times shorter, while generating around 30% less in effluent volumes. This column was also coupled simultaneously to electrospray ionisation mass spectrometry (ESIMS) and inductively coupled plasma mass spectrometry (ICPMS). The instrumental set-up was performed in a conventional laboratory, by taking into account the geometrical constraints existing in the laboratory dedicated to radioelement analysis. Furthermore, separation of the series of lanthanide (Ln) species was demonstrated for the first time thanks to the separation mode of hydrophilic interaction liquid chromatography.

Bk and Cf chromatographic separation and ²49Bk/²48Cm and ²49Cf/²48Cm elemental ratios determination by inductively coupled plasma quadrupole mass spectrometry.

The French Atomic Energy Commission has carried out several experiments for the study of minor-actinide transmutation processes in high intensity thermal neutron flux. In this context a Cm sample enriched in (248)Cm (∼97%) was irradiated in a thermal neutron flux at the High Flux Reactor (HFR) of the Laue-Langevin Institute (ILL). The precise and accurate determination of Cf isotope ratios and of (249)Bk/(248)Cm and (249)Cf/(248)Cm elemental ratios in the (248)Cm irradiated sample is crucial for the calculation of actinide neutron capture cross-sections. This work describes an analytical procedure for the separation and the isotope ratio measurement of Bk and Cf in the irradiated sample. The Bk and Cf separation is based on a lanthanides separation protocol previously developed by the laboratory. Well-defined retention times for Bk and Cf were obtained by coupling the Ionic Chromatography (IC) with an ICP-QMS. All conditions of element separation by IC and the different steps of the analytical protocol in order to obtain the isotopic and elemental ratios are presented. Relative uncertainties of Cf isotopic ratios range from 0.3% to 0.5% and the uncertainty of the (249)Bk/(248)Cm and (249)Cf/(248)Cm elemental ratios are respectively 6.1% and 3.2%. This level of uncertainty for both isotopic and elemental ratios is in perfect agreement with the requirement for transmutation studies.

Development of cadmium/silver/palladium separation by ion chromatography with quadrupole inductively coupled plasma mass spectrometry detection for off-line cadmium isotopic measurements.

A separation method was investigated to perform off-line cadmium isotopic measurements on a (109)Ag transmutation target. Ion chromatography (IC) with Q ICPMS detection (quadrupole inductively coupled plasma mass spectrometry detection) was chosen to separate cadmium from the isobarically interfering elements, silver and palladium, present in the sample. The optimization of chromatographic conditions was particularly studied. Several anion and cation columns (Dionex AG11(®), CS10(®) and CS12(®)) were compared with different mobile phases (HNO(3), HCl). The separation procedure was achieved with a carboxylate-functionalized cation exchange CS12 column using 0.5 M HNO(3) as eluent. The developed technique yielded satisfactory results in terms of separation factors (greater than 5) and provides an efficient solution to obtain rapidly purified cadmium fractions (decontamination factors higher 100,000 for silver and palladium) which can directly be analyzed by multi collection inductively coupled plasma mass spectrometry (MC ICPMS). By applying the proposed procedure, accurate and precise cadmium isotope ratios were determined for the irradiated (109)Ag transmutation target.

No major effect of orciprenaline and propranolol upon ACTH-induced cortisol secretion.

Preclinical research suggests adrenal beta-adrenergic receptors to be involved in the regulation of steroid synthesis. In a group of healthy male volunteers, we compared ACTH-induced cortisol and dehydroepiandrosterone (DHEA) secretion after pre-treatment with orciprenaline, propranolol or placebo. Neither baseline nor ACTH-induced steroid secretion differed between these conditions. Our data do not support the hypothesis that the adrenal beta-receptor plays a major role in steroid secretion in humans.