Determination of 210Po and uranium in high salinity water samples

A method for the determination of uranium and Po-210 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 U-235 and U-238 can be directly determined by ICP MS method with a detection limit of 0.01 ppb for U-238. Prior to a selective determination of Po-210, the majority of other naturally occurring a-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-210 is simply separated by direct transfer to an extractive scintillator containing 5% of trioctylphosphine oxide in Ultima Gold F cocktail and determined by an alpha/beta separation liquid scintillation technique with detection limit below 0.1 mBq/dm(3)