Uranium U

The basic methods for determining uranium are provided. The vanadatometric determination of U is based on titration of U(4) with ammonium vanadate in the presence of N-phenyl-anthranitic acid used as the indicator. The determination is hindered by Fe(3), Ti(4), Mo(6) and Sn(4). The complexometric determination of uranium is based on formation of complexes of U(4) with EDTA. The titration is carried out at pH=1.7 in the presence of arsenazo 1 as the indicator. The determination is hindered by Th, Zr, Sc, In and Ti, which must be separated. The method is applicable for determining U in alloys with Mg, Al, Fe, Si, in industrial salts and oxides. U(6) is determined photometrically with the aid of arsenazo 3 (pH=1.7-2.5). The determination is hindered by Th, Zr, Al, Cr(3) and lanthanides. In the presence of diphenylguanidinium chloride and EDTA, the dyed compound is extracted with butanol. U is determined photometrically in alloys with zirconium by means of chlorophosphonazo 3. Zr and Hf are masked with NH4F, while Ti is masked with hydrogen peroxide