ISO 10981:1993

The principle of the method specified is diluting the sample in aqueous ascorbic acid solution until the amount of free acid of the nitric solution injected into the chromatograph is lower than 0,1 mol/l in HNO3, performing ion-pair partition chromatography, detecting the elution of uranium by UV spectrophotometry at a wavelength of 254 nm, measuring the peak area, obtaining the result by comparison with the measurements of standards. Applies to uranium concentration between 0,1 g/l and 500 g/l. Specifies how interference by nitrite and plutonium ions is prevented.