A universal solvent extraction-titration method for the rapid and accurate determination of uranium in complex solutions

Abstract A rapid and accurate method has been developed for the determination of uranium in complex solutions produced in the recovery of uranium from nuclear fuels. These solutions usually contain 0.1–20 g U l -1 and high concentrations of aluminum nitrate in addition to a variety of cations and anions associated with fuel-element constituents and dissolution media. The method involves the solvent extraction of uranium from an acid-deficient aluminum nitrate-tetrapropylammonium nitrate solution into 2% tributy1 phosphate in n-amy1 acetate. The uranium is then backextracted with a concentrated phosphoric acid solution, and titrated by the method of Davies and Gray. The uranium extraction efficiency for sample solutions weighing up to 50 g is 99.9% or better, and the limit of error per analysis with 95% confidence is ±0.6%. No prior sample preparation is necessary, no expensive equipment is required, and even unskilled personnel can do duplicate analyses in 1.5 h.