Attractive approach to analyse trace and ultra-trace elements on transmutation targets by direct separation of isobaric interferences using collision reaction cell implanted on MC-ICPMS

The experiments involved in the PHENIX french nuclear reactor to obtain precise and accurate data on the total capture cross sections of the heavy isotopes and fission products require isotopic ratios measurements with uncertainty of a few per mil. These accurate isotopic ratio meaurements are performed with mass spectrometer equipped with multicollector system. The implantation of collision-reaction cells on Multiple-Collector Inductively Coupled Plasma Mass Spectrometer offers the possibility to separate directly in the cell several interfering elements. We present three applications of direct separation in a collision reation cell in the case of three transmutation targets: 235 U, 153 Eu and 95 Mo. Three different reactions gas NH 3 , O 2 and N 2 O were used to separate respectively Pu-U, Eu-Gd-Sm and Mo-Zr interfering elements. This approach is of great interest to reduce the risk of natural contamination, the amount of analytical radioactive waste, and the time contact of analysts with radioactive samples.