The stability of plutonium sulphate tetrahydrate, an analytical standard: a ten-year evaluation.

The stability of plutonium sulphate tetrahydrate, Pu(S0(4))(2).4H(2)O, an analytical standard for plutonium, has been studied over periods of up to 10 years, and at relative humidities of 95% and les than 0.1%. The material was found to be stable with time; it was slightly affected by extremes of humidity but the changes were readil reversible.

Improved method for the constant-current potentiometric determination of plutonium.

A highly precise method is described for the determination of plutonium by constant-current potentiometric titration with primary standard potassium dichromate. The relative standard deviation is 0.04% or better.