1991 Volume 7 Issue 6 Pages 931-933
An uranyl ion (UO22+) reacts with 2-(p-methylphenylazo)pyridine in thiocyanate system. The species is extractable quantitatively into methyl isobutyl ketone (MIBK) in the presence of nitrate ion, showing an absorption maximum at 370nm. Beer′s law is obeyed over the range 0.15-1.5μg of uranium/ml. The molar absorptivity and Sandell′s sensitivity are 0.166×104 l mol-1 cm-1 (on the basis of uranium content) and 0.0014μg/cm2, respectively. Various international geochemical reference samples were chosen to check the validity of the method. The results obtained were in good agreement with the published data.