A simple potentiometric method for the determination of free acidity in presence of hydrolysable ions
and sequential determination of hydrazine is developed and described. Both free acid and hydrazine are
estimated from the same aliquot. In this method, free acid is titrated with standard sodium carbonate
solution after the metal ions in solutions are masked with EDTA. Once the end point for the free acid is
determined at pH 3.0, an aliquot of formaldehyde is added to liberate the acid equivalent to hydrazine
which is then titrated with the same standard sodium carbonate solution using an automatic titration
system. The described method is simple, accurate and reproducible. This method is especially applicable
to all ranges ofnitric acidandheavymetalionconcentrationrelevantto Purexprocessusedfornuclear fuel
reprocessing. The overall recovery of nitric acid is 98.9% with 1.2% relative standard deviation. Hydrazine
content has also been determined in the same aliquot with a recovery of nitric acid is 99% with 2% relative
standard deviation. The major advantage of the method is that generation of corrosive analytical wastes
containing oxalate or sulphate is avoided. Valuable metals like uranium and plutonium can easily be
recovered from analytical waste before final disposal.