Impurities are separated from plutonium solutions by means of TTA (thenoyltrifluoracetone) extractions. Plutonium in hydrochloric acid solution is reduced to the trivalent state with hydroxylamine, and some impurities are extracted into hezone or a solution of TTA in hezone. The organic phase is removed, and the plutonium in the aqueous phase is oxidized to the tetravalent state with nitric acid. Investigations of several variables which affect the extraction are described..