Kinetic determination of uranium(IV) based on its catalytic effect on the phosphomolybdic acid-iodide reaction

A kinetic spectrophotometric method has been developed for the determination of trace amounts of uranium(IV) based on its catalytic effect on the phosphomolybdic acid iodide reaction. A significant feature of the proposed procedure is the selectivity for uranium(IV); it enables the determination of trace amount of uranium in the presence of large excess of rare metalions and other cations and anions. The method can be applied to the determination of uranium within the concentration range of 0–12μg· cm^?3, and the detection limit of the method is 0.02μg·cm^?3. Trace amounts of uranium in thorium nitrate and scandium oxide had been determined by the procedure and the results are satisfactory.