orang: 7 40 4.2 Procedures for Alpha Emitting Radionuclides 4.2-1 Chentcal areceducves used for isulating plutonium and uranium. Senaration of plutonium and urantum from the high calcium- salt solutions was initially accomplished by employing solvent extraction, using the liquid-liquid anion trijsoctylamine (TIOA) procedure of Butler (1968), followed by the anion exchange resin (column) technique described by Harley (1972). Both anion exchange procedures rely on the necessity (and ease) of maintaining the plutonium and uranium in the +4 and +6 oxidation states, respectively. Both methods used retain the actinides; however, the early work indicated that neither method hy itself was sufficient to reduce the salt content of the enriched fraction enough to yield high resolution alpha spectra when the samples were subsequently electroplated (by the method of Talvitie, 1272). The advantage of the liquid-liquid jon exchange procedure of Butler is its speed of use and its high decontamination factor for the removal of 28a Its disadvantage is that it will not efficiently exchange either Pu or U from high ca** concentration solutions imposed by the coralline sample ratrix. On the other hand, the anion exchange resin technique in Harley (op. cit.) removes the salts, but does not completely remove 2285, The advantage of using both techniques together are the very high decontamination factors provided for the removal of interferring radioisotopes and the near complete absence of inorganic salts in the final sample. During approximately the first two-thirds of the laboratory work, the TICA procedure was employed before the resin anion exchange step. Low chemical yields were found when using this sequence of procedures, and resulted in a high error term in the measurement of 2385, and uranium in several samples. using the column ion exchange hefore the liquid-liquid ion exchange, ®&y