SAMARIUM 



293 



Samarium 153 (47 hr) 



Cat. No. Sp. Ad. 

 Sm-153-I 1 mc/mg 



Critical Org. 

 Bone 



Form 



SmaO, 



Beta 0.68, 0.80 Gamma 0.0695-0.61 



Cost Chem. Cont. Radiochem. Cont. 



$9/8.6 mc — 0.002 mc Ku'" (1.7 yr) 



Rf/mc 

 1 







Intake Levels. Samarium is one of the rare-earth elements and has 

 not been of biological interest. 



Radioassay. In order to obtain preparation Sm-153-I, the target 

 material must be supplied by the investigator. The Eu'^*^ radioeontam- 

 ination becomes of increasing importance with the age of the sample. 

 The contribution of the Eu'^^ in a sample could be corrected for by making 

 the original count, then making another count about 470 hr later, at 

 which time the Sm''^^ would have decayed to about 0.1 per cent of its orig- 

 inal count. This latter value would be subtracted from the original (see 

 Chap. 5 for a general treatment of the assay of mixed radioisotopes). As 

 an alternative, the europium could be separated by chemical procedures. 



