-20more sharply defined in the separations. of the 7 peaks attributed to Co!” The relative heights C028 | and Co 60 were un- changed (Fig. 4). The low yield of cobalt by the a@ -nitroso- # -naphthol precipitation technique is due partly to loss of cobalt on the iron scavenge utilized in the technique and to high self-absorption in the sample’. (2) Separation of cobalt by the Los Alamos method (Klein- berg, 1954). From an original 5,330 c/m B in each of the dupli- cate samples, totals of 4,490 and 4,730 c/m & were recovered in the cobalt separations made by the Los Alamos method. The 7 spectrum curves were essentially the same as those of the original sample and as those from the @ -nitroso- f -naphthol co- balt separations. After the cobalt separations were made by the Los Alamos method, vanadium separations (Meinke, 1949) were done. a..12 and .08 MEV and in both y 7 and an approximately one-year half life energy and half life resembles Co!” determine that the observed .12 MEV were made. It was found thit the separations was not significantly counted either for 8 or 97 In orderto 7 peak in the cobalt sepa- rations was from Cop! and not from vio, when v'9 has the vanadium separations activity in the vanadium greater than . Therefore, background the .l2 Potassium cobaltinitrite precipitation and extraction of cobalt thiocyanate complex into amyl alcohol ether, with appropriate scavenging steps. (as described in Collected Radiochemi- cal Procedures, LA-1721)