Constant current coulometric method for the determination of uranium in active process solutions

The determination of uranium in the range of 2.5-5 mg by constant current coulometry is described. The procedure is based on the modified version of the DAVIES - GRAY method, wherein uranium, after the reduction step, is oxidized by adding a known amount of potassium dichromate, and the excess of dichromate is determined by titration with Fe2+ solution. Fe2+ ions needed for the titration are generated in situ with 100% current efficiency by electrolytic reduction of Fe3+. The method is found to be accurate with a coefficient of variation better than 0.2%. (author)