244 EUROPIUM 



Europium 152 (13 yr) Beta 0.9, 1.7 Gamma O.'S, 1.2 K 



Europium 154 (16 yr) Beta 0.3, 0.7, 1.9 Gamma 1.2 



Cat. No. Sp. Act. Form Cost Cheni. Cont. Radiochem. Cont. 



Eu-152154-I 72mc/g Oxalate $781/440 mc — — 



MicaW. Int. C. Scint. C. Rf/mc bQ% Self-ahs. 



9.1 X 10-4 6 6 X 10-< 6.7 X 10-3 6 25 (calc.) 



Critical Org. Body Air Water Effect. Ty^ 



Bone 22^0 6 X lO'^ 3 X 10"^ 820 days 



Intake Levels. Europium, one of the rare-earth elements, has not been 

 of interest biologically, and little or no information is available regarding 

 its occurrence in plant and animal tissues. 



Radioassay. From the listed energies it would appear that routine 

 beta or gamma counting would be satisfactory. 



Chemistry. From comparison with radioisotopes of other rare-earth 

 elements, it would seem that wet- or dry-ashing could be employed with- 

 out danger of losses. However, this should be checked by the investiga- 

 tor. One might also expect radiocolloid formation in the dosing solution 

 to be a problem. An iodometric method for chemical estimation has 

 been reported (Eu-1). 



Typical Methods. Rats were given 50 hq, either intravenously or 

 intramuscularly, and autoradiographs made of the tissues (Eu-2). 



Eii-1. Scott, W. W.: "Standard Methods of Chemical Analyses," 5th ed., vols. I and 

 II, D. Van Nostrand Company, Inc., New York, 1939. 



Eu-2. Van Cleave, C. D.: A Radioautographic Study of the Localization of Radio- 

 active Europium in Certain Soft Tissues of the Rat, Anat. Record, 103: 514-515 

 (1949). 



