Determination of (210)Po and uranium in high salinity water samples

A method for the determination of uranium and (210)Po in high salinity water samples has been elaborated. Both radionuclides are preconcentrated from 0.5 dm(3) saline media by co-precipitation with hydrated manganese dioxide, followed by dissolution of the precipitate in 200 mL of 1 M HCl. Uranium isotopes (235)U and (238)U can be directly determined by ICP MS method with a detection limit of 0.01 ppb for (238)U. Prior to a selective determination of (210)Po, the majority of other naturally occurring α-emitting radionuclides (uranium, thorium and protactinium) can be stripped from this solution by their extraction with a 50% solution of HDEHP in toluene. Finally, (210)Po is simply separated by direct transfer to an extractive scintillator containing 5% of trioctylphosphine oxide in Ultima Gold F cocktail and determined by an α/β separation liquid scintillation technique with detection limit below 0.1 mBq/dm(3).