Studies on the individual potentiometric determination of uranium and plutonium in a single aliquot have been initiated recently
in our laboratory. It was required to adapt the reported procedures (for the precise determination of uranium and plutonium
individually when present together in a sample) at various stages to make them suitable for the successive application of
the procedures to the same aliquot. Two alternative schemes are proposed in the present work. In the first, plutonium is determined
by HClO4 oxidation followed by the determination of total uranium and plutonium by Zn(Hg) reduction. In the second, plutonium is determined
by AgO oxidation following the determination of total uranium and plutonium by Zn(Hg) reduction. Amount of uranium is computed
in both cases from the difference of two determinations. Precision for the assay of plutonium and uranium was found to be
±0.25% and ±0.35%, respectively, at milligram levels.