stm an me ee eeee we me gaa SCOTUM by G. Fulmer and 38. Intorre A.6 INTRODUCTION The sodium is separzted from the fission products by eluting the sample. from a column of colloidal Dowex-50 cation resin. The sodium fraction of this elution contains some anions which ean be removed by a subsequent elution of this fraction from an anion column of Nalcite SAR resin. The sodium fraction from the anion elution is finally Slurried with fine mesh Towex-50 to adsorb all the sodium present. The resin ts then filtered on Whatmen £50 paner and mounted for counting, This separation was a 190 per cent chemical yield, A.7 PEAGENTS Colloidal Dowex-50 cation resin Dowex-50, cation, resin, below 400 mesh Naleite SAR resin, 20-50 mesh HCl 0.5 N hte A.8 PROCEDURE 1. Prepare a glass column, i1 mm inside diameter, with glass wool plugging the restricted lower end. This column is filled with colloidal Dovex-50 resin slurried in O.5N HCl] to a settled bed height of 11 + 0.5 em.. Any excess resin in the colurn is removed by slurring the resin with additional 0.5 NHCl and drawing the excess from the top of the column with a syringe, Then the column is conditioned by washing with 10 ml of 3 N NaCl followed by 100 ml of 0.5 N HCl. This cycle is repeated three tires (Note 1). 2. A sample containing not more than 15 mg of NaCl (usually 1 to 2 ml) is added to the column after the 0.5N HCl has drained to the top of the resin bed. Care is taken to add the sample directly to the top layer of the resin without contacting the sides of the column. After the semple has drained to the top of the resin, sufficient 0.5N HCl is carefully pipetted onto the resin to prevent slurrying when the 0.5 N uC1l reservoir is connected. 3. After the 0.5N HCl reservoir has been connected, the elution flow rate should be avrroximately 1.5 mi/min (note 2), ml of eluate are discarded. The first 30 The next 40 ml, which contain the sedium along with some anions such as molytdate, ruthenate, and, Lodate, na 6 are collected for addition to an anion column. RicheutileSemeninae 49 SECRET — RESTRICTED DATA