LIQUID-LIQUID-EXTRACTION OF URANIUM(VI) WITH CRYPTAND-222 AND EOSIN AS THE COUNTER ION

Uranium(VI), (5 mu g) was quantitatively extracted at pH 6.0 with 0.01 M cryptand-222 in chloroform in the presence of 0.005M Eosin as the co unter ion. The metal from the organic phase was stripped with 0.1M per chloric acid. Uranium(VI) from the aqueous phase was determined spectr ophotometrically at 430 nm as its complex with oxine. The extraction w as quantitative between pH 5.5-6.5. Nitrobenzene, chloroform and dichl oromethane were the best diluents. The optimum extractant concentratio n was 0.01M, while that of Eosin was 0.005M. Except for perchloric aci d (0.01M), other acids could not strip uranium. Uranium was separated from manganese, cadmium, lead, thallium and nickel, etc., in the multi component mixtures. The relative standard deviation was +/-1%.