and dilute to 1 liter with HzO. Remove a 2 ml aliquot of the solution, make the solution basic with cone. NH,OR, and dilute to 20 mi. Precipitate the calcium oy adding a slight excess of saturated solution . of (NHu)2Ce0y. Filter on a sintered glass Gooch crucible; wash the precipitate ‘with 10 ml of ethanol and 19 ml of ether. ' * Vacuum desiccator for one hour. A.4 PROCEDURE - 1. Suck dry on the ° “Weigh the precipitate as Ca C20),.H20 . To the sample add 2 rl of ealetum carrier (10mg/m1) and 16 mg of Pd and precipitate with HgS. Add 3 drops of 0.1% solution of Aerosol OT, centrifuge and discard precipitate. 2. is basic. clear. 3.. Boil out H2S and add conc. NHWOH carefully until the rolution Centrifuge and discard precipitate if the solution is not ‘ . Heat to boiling and precipitate calcium with 2 ml of saturated K2C03.. Centrifuge and discard suvernate, . ' &, Dissolve precipitate with Z ml of 6N HNO3 and heat to eliminate the COg. Meke the solution basic with NHyOH and dilute to a volume of 20 ml. (Note 1). : , _ Se, Add 10 mg of Fe, centrifuge, and discard the precipitate. Repeat the iron scavenging step twice. 6. To the supernate add 10 mg of Cs, heat to boiling, and precipitate the calcium with 2 ml of standard saturated K2C03. Centrifuge and discard the suvernate, Wash the precipitate with 5 ml of H20 and discard washings. Dissolve the precipitate with 1 ml of conc. HNO3. ‘ 7 Add 10 mg of Ba and 10 mg of Sr carriers to the solution and precipitate the Ba and Sr nitrates with 25 ml of cold fuming HNO3 in an 4ce bath. Centrifuge and discard the precipitates. Add 10 mg of Ba carrier and 5 ml of cold fuming HNO3 to precipitate Ba(NO )o again. Centrifuge and transfer supernate to a 125 ml Erlenmeyer flask. 8. Boil down to § ml on a hot plate and transfer to a centri- fuge tube. Wash the Erlenmeyer flask twice with 3 ml of H20 adding the washings to the centrifuge tube. 9. Add cone, NHXOR carefully until the solution is basic. If necessary dilute with water to 20 ml volume (note 1). Add 10 mg of Fe carrier to precipitate Fe(OH)3. Centrifuge and discerd precipitate. Repeat the Fe(OH)3 scavenging step. 10. Heat the supernate to boiling and add 5 ml of a saturated solution of (NHj,)2C20,. Digest in a water bath to coagulate precipitate. Filter on Whatman #40 paper; wash with 5 mi of 420, 5 ml of ethyl alcohol, and § ml of ethyl ether. Ury in a vacuum desiccator for 1 hour and weigh as CaC20,.H20. The chemical yield is approximately 25%. A.5 NOTE: The volume of the solution at this point must be largs enough to eliminate loss of calcium as the hydroxide in the ferric hydroxide scavenging step. 48 SECRET - RESTRICTED DATA ~ .