Determination of traces of free acid in uranyl salt solutions

A method for the determination of free acid in the presence of uranium(VI) is suggested. It involves the extraction of uranium by TBP from a solution saturated with potassium nitrate or chioride in order to prevent interference from the hydrolysis of uranium. The end-point is detected potentiometrically at pH 3.4. The method is suitable for the determination of 0.1–1.5 millimoles of acid in the presence of as much as 1.0 millimole of uranium.