Radionuclide analysis based on lab-on-chip liquid-liquid extraction

The analysis of radionuclides present in high and medium activity wastes is carried out according to operating protocols including the sequence of many steps of separation/purification. In order to improve these protocols, the micro-fluidic tools have their place. In particular the liquid-liquid extraction in micro-system shows various interests: very few solvent is consumed, the process can be automated and parallelized and the extraction and the stripping can be coupled on a single chip. Liquid-liquid extraction with continuous flow in microsystems has not been tackled until recently since only few chemical systems have been studied, in particular in the nuclear field. Thanks to the characteristics linked to the miniaturization (large specific area, short diffusion length, low reagents volumes), our objective is to control the fluid hydrodynamics for optimizing the contributions of diffusion and convection to the mass transfer in solutions. An exhaustive bibliographical review about the liquid-liquid extraction of metal species on lab-on-chips and preliminary experimental results will be presented and discussed. (authors)