Zr and U determination at trace level in simulated deep groundwater by Q ICP-MS using extraction chromatography.

In the framework of trace element analysis by Q ICP-MS in a simulated deep Callovo-Oxfordian groundwater, separation procedures based on extraction chromatography were developed to eliminate the high salt contents and to concentrate Zr and U simultaneously. Theoretical and experimental speciation studies showed the importance of adjusting the medium to HNO3/HF (0.5 M/0.005 M) to guarantee the stability over time of the analytes before removal of the matrix. Two preconcentration methods based on TRU and TODGA resins were optimized for the simultaneous isolation of Zr and U prior to Q ICP-MS measurements. Using TRU resin, alkali and alkali earth metals contained in the deep groundwater were removed with 2 M HNO3 whereas Zr and U were recovered with a HNO3/NH4HC2O4 (0.02 M/0.05 M) medium. For the separation protocol based on TODGA resin, alkali and alkali earth metals were eliminated with 3 M and 11 M HNO3 while Zr and U were simultaneously stripped with a HNO3/HF (0.5 M/0.2 M) medium. The procedure optimized on TODGA resin was validated with the French AFNOR NF T90-210 standard by studying linearity, limits of quantification (LOQ) and separation yields. The LOQ was determined at 0.008 µg L(-1) for Zr and U after the separation. Both analytes were recovered quantitatively. Compared to a sample dilution implemented to reduce the matrix effects, the developed preconcentration method allowed improving the sensitivity up to a 20 fold factor for Zr and U measurements at trace level by Q ICP-MS.

Synthesis and characterization of ammonium functionalized porous poly(glycidyl methacrylate-co-ethylene dimethacrylate) monoliths for microscale analysis and its application to DNA purification.

A systematic study of parameters affecting the nucleophilic addition of secondary and tertiary amines on reactive epoxy groups was conducted on porous polymer monoliths. Reaction of small amines like diethylamine (DEA) or triethylamine (TEA) on poly(glycidyl methacrylate-co-ethylene dimethacrylate) monoliths (poly(GMA-co-EDMA)) allows to prepare anion exchange media. This study aimed to determine optimal and suitable conditions to prepare anion-exchange porous monolith inside 100 microm internal diameter capillary. The reaction kinetic of amine nucleophilic addition on porous poly(GMA-co-EDMA) monoliths was followed by FTIR-ATR spectroscopy. The reactivity of such epoxy-functionalized porous polymers was first determined through a study in pure amine solutions. Thereafter, conditions of reactions (i.e., temperature and time of reaction, solvent composition, concentration of amine) with respect to its further implementation at nanoscale, were optimized through a factorial analysis. The optimization allowed extending conversion yields of epoxy groups up to more than 90% in dilute amine solution within less than 4 hours of reaction for TEA addition. This ion-exchange support with respect to the in-situ light-addressable process of elaboration is specifically designed to be incorporated as biomolecular sample preparation module in microsystem devices. The high loading capacity obtained for the preconcentration of DNA demonstrate the attractivity of this functionalized polymeric porous monolith as solid-phase support to improve the quantity and the efficiency of DNA extraction applied into microscale format like capillaries or lab-on-chip.

Determination of (93)Zr decay scheme and half-life.

This study describes a new determination of the decay scheme and half-life of (93)Zr. A pure (93)Zr solution was obtained after chemical separation from the dissolution of an irradiated zircaloy sample. The concentration of (93)Zr in the solution was measured by mass spectrometry, with an isotopic dilution technique. The activity of the solution was measured by liquid scintillation counting, using an efficiency tracing method. The measurement of the activity concentration of (93)Nb(m) by X-ray spectrometry, allowed the determination of the (93)Zr decay scheme and the calculation of the (93)Zr detection efficiency. This leads to the calculation of the decay probability of (93)Zr toward (93)Nb(m) of (0.73+/-0.06) and to a half-life of (93)Zr of (1.64+/-0.06)x10(6) years. These values are discussed in comparison with the evaluated values available in the literature.