The influence of acetone on the extraction of Th(IV) and U(VI) from aqueous solutions of nitric acid by solutions of Amberlite
LA-2 and trilaurylamine in cyclohexane has been investigated. The partition of nitric acid and acetone between the two phases
is discussed. The change of the distribution ratios of Th(IV) and U(VI) by adding acetone to the liquid-liquid-system is explained
by the shift of the equilibrium of the metal nitrate complexes and by the increase of the concentration of nitric acid in
the organic phase.