Developing a rapid method for the determination of uranium in pure phosphoric acid and D2 EHPA

Arsenazo (III) used in titrate uranium spectrophotometrically in phosphoric acid after its extraction into organic phase. In this work we used arsenazo(III) to complex uranyl ion in pure phosphoric acid and in the aqueous phase. The spectrum of the complex shows that λ max is at 650 nm. The linearity of the method is corelated with acid molarity, it is (1 -4, 10 - 30, 10 - 40) ppm uranium for (0.2, 1, 2) M of phosphoric acid respectively. Uranium in D2 EHPA stripped by phosphoric acid and then determined by this method. Also it has been applied to determine uranium in pure perchloric acid. The method is direct, rapid, very cheap and relatively accurate. (author)