Automatic potentiometric determination of uranium in the presence of vanadium in mixed solutions of inorganic acids and ethanol

The effect of V on quantitative determination of U in solutions in the presence of phosphoric and sulfuric acids and of ethanol was studied. The nonexcludable component of the systematic error and Student’s test were chosen as criteria of the result validity. In phosphoric acid solutions, the presence of V leads to overestimation of the analysis results due to joint titration of V and U. The addition of Fe(III) in the course of sample preparation eliminates this effect. The underestimation of the analysis results, appearing in this case, is eliminated by adding sulfuric acid and ethanol in a definite ratio. For U determination in the presence of V, the media can be ranked in the following order with respect to analysis efficiency: phosphoric acid < phosphoric acid + ethanol < phosphoric acid + sulfuric acid < phosphoric acid + sulfuric acid + ethanol. The optimum medium for the U determination in the presence of V, allowing the permissible U/V weight ratio to be increased from 1 : 0.5 to 1 : 10, was determined.