~B= fhe resin was then added to the column and 30 ml of 12 M HCl were allowed to pass through under pressure at a flow rate of 0.1-0.2 ml per minute to remove the iron impurities in the resin, The sample was added to the column and the eluates were collected as deseribed above at a flow rate of 0.5 ml per minute. Next, 8-13 ml of the following molarities of HCl were added successively: 12, 6, 4, 2.5, 0.5, 0.005 and 0, and the fractions were collected separately. The resin was removed from the column and ignited for assay. 4. Identification of the nuclides present in the fractions One~-ml aliquots of each oxalate or citrate fraction were placed on stainless steel planchets 14 inches in diameter, dried under heat lamps, and counted in a methane gas-flow chamber or an end window counter containing a 2-inch diameter Anton Geiger tube. The HCl fractions, however, were first taken to dryness, treated with a few drops of concentrated nitric acid, dried, and rediluted to the original volume with water. One-ml aliquots of these fractions were then placed on stainless steel planchets as above and dried. The remainders of the fractions containing significant amounts of radioactivity were dried and analyzed in a single- channel, 50-position, automatic~advance, gamma spectrometer using @ 2-inch, well-type sodium iodide crystal. and 8 Radioactive decays mass absorption curves were obtained for some of these fractions. Correction factors for converting & and #% counts to disintegrations per minute were calculated by the use of standards ak, ped . oa or al