NEW METHODS OF TRANSPLUTONIUM ELEMENT SEPARATION AND DETERMINATION

Some recently developed new methods of separation and determination of transplutonium elements (TPEs) are described. The solvent extraction of TPE(III) by bidentate organophosphorus reagents from strongly acidi c, salt-containing media and their extraction from alkaline solution b y various reagents as well as isolation of TPEs in ''unusual'' oxidati on states are discussed. Stabilization of americium as Am-IV, Am-V, Am -VI and berkelium as Bk-IV is considered. The separation of actinides and rare earth elements can be carried out by countercurrent chromatog raphy which is based on the retention of the organic phase in a rotati ng column of a planetary centrifuge under the action of centrifugal fo rces while the stationary phase is continuously pumped through. It has been shown that TPEs can be successfully separated by this technique. Attention has been paid mainly to consideration of contemporary metho ds for determination of actinides, special distinction of such methods being low limits of determination, high precision and selectivity. A large number of coulometric methods for determination of americium and berkelium characterized by high precision and selectivity as well as luminescence methods have been developed.