Isotope __ Observed Fxpected vercent percent ar? Ratia observed percent expected vercent 3.8 8.2 1/2 RutO3+106) pt 13.0 ag. 19.5 1/1 got th th pri 26.0 13.2 2/1 par? 3.1 10.8 1/4 Triv. RE. 5.7 3/1 ve —"ha ai sor Sigle cc ik ae er acter oSSas ee 39 this solu tion Was a Mixtume O1 In addition to the great individual variation, differences were also observed in the total smount of activity accounted for. At stations 9C and 9D, both of which are within 45 miles of Bikini Atoll, only about 80 percent of the total beta activity was eccounted for as Pission products. trum run on sample 9D about 5 percent of the total gamma activi- ty was Zn 65 other hand, No evidence of cobalt isotopes was found. ctrgera ph gindicates topes C On the in the gamma spectrum curve of plankton from station 8C. €5 miles poe? 9 northwest of Bikini, the non-fission product iso65 Zn ~ and posetbly Co 57% , accounted for more than 50 percent of the total qumma activity on November 26, 1956**. (Fig. 10). » on Of the Marsh samples, chemical separations for fission prod- ucts and zine and cobalt were made on plankton from stations 5, 42 and 55 (Table 6). * The chemigg1 and resin column data indicate the possible Presence of Co-'. The gamma spectra mage on the separations, etapaAlleccteh are ghARCSi + 3 “Yo@P© Rh Gant Og } 7 On the basis of a gamma spec- however, indicate that the isotope is V*9 rather than Co-/. ** The techniques employed for identifying the different co- balt isotones involve the’use of chemistry, ton exchange resin Columns, beta energy determinations, and gamms spectrometry. The techniques and results obtained for vartous biological sam- Ples will be published in a later paper.