Determination of Po and uranium in high salinity water samples.

A method for the determination of uranium and Po in high salinity water samples has been elaborated. Both radionuclides are preconcentrated from 0.5 dm saline media by co-precipitation with hydrated manganese dioxide, followed by dissolution of the precipitate in 200 mL of 1 M HCl. Uranium isotopes U and U can be directly determined by ICP MS method with a detection limit of 0.01 ppb for U. Prior to a selective determination of 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, 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.