-68- AECD-3446 excess of concentrated NH40H was added and the solution was heated almost to boiling and saturated with HS. The iron and manganeseprecipitates were remomg Ee by centrifuging, the calcium was precipitated as oxalate, separated by centrifugia, dissolved in a minimum amount of sulfuric acid and the oxalate was removed by treatment with permanganate solution. = Another ten milligrams of ‘Fettt WAS addeg 3 Ee to the solution and the precipitation of iron and manganese repeated. The Calciugs 2 was again precipitated as oxalate in the solution acidified with HCl, the Precipitare 4 e was washed with 0.1% ammonium oxalate solution, and the calcium oxalate wag transferred to a stainless steel counting disk, weighed, and counted, a ° . SCAVENGING: Procedure it’ (Revised Procedure including more vigorous scavenging.) ¥ = Element Separated; Calcium, from all other elements, S @}) To aliquot of the HNO, digested soln. add 10 mg each of Ru, Fe, and La, (2) Add 10 mg Ru and 10 Bi to supn. and repeat H,S pptn. (3) Add 10 mg Fe and 10 mg Y to supn. and repeat NH, pptn. = (4) Boil out H,S and ppt. with NHg. (5) Boil down to approx. 5 ml, add 10 mg Ba and 10 mgSr and ppt. with cold ;x Fuming HN0O,. 3 Make 0.5N in HCl and ppt. with HS. (6) Add more Sr and Ba to supn. and repeat pptn. 3 times. (7) Add Sr alone and repeat 2 times more, (8) (8) 2= = 4 2 Boil down to approx, 5 ml, add 5 ml sat. (NH,),C,0, and make basic with = ae NHg. x basic make and KCl0, with Cy04 destroy Dissolve CaC,0, ppt. in HNO,, with NHg. Add 10 mg eachof Fe, La and Y. Centrifuge. —-----. -.- ~g (10) Add more Fe, La and Y to supn. and repeat pptn. Centrifuge. = (11) Repeat step (5). é (12) Boil supn, down to approx, 5 ml make basic with NH,, heat, add 5 mi #8. Ss (NH,)C>0, slowly. Stir 2 min., centrifuge, wash 3 times with 5 ml Hy’ 3 times with 5 ml 95% EtOH, 3 times with 5 ml ether. (13) a Transfer the total ppt. onto stainless steel disk and spread uniformly over = 9 em? area, dry and count. __-~§ lW. W. Meinke, UCRL 432, Aug30, 1949. Chemical Procedure used in bombsre” aa steers — ment work at Berkeley.