ANTIMONY 



205 



Antimony 122 (2.8 days) 



Cat. No. Sp. Act. Form 



Beta \.'M. 1.94 



Gamnta 0.57 



Sb- 122-1 250mc/g 



Metal 



Cost Chern. Cont. Radiorhem. Conl. 



;i2/50 mc — 1.4 me Sb'^^ (GO days) 



Rf/mc 

 3.4 



Antimony 124 (GO days) 



Cat. No. Sp. Act. 



Sb-124-I 12 mc/g 

 Sb-124-P 500-1500 mc/g 



Mica W. Int. C. 



Form Cost 



IMetal " $33/2.4 mc — 



Chloride $3/mc — 



Scint. C. 



Beta 0.5-2.37 Gamma 0.121-2.3 



Chem. Cont. Radiochcni. Cont. 



20 mc Sb'" (2.8 days) 



Rf/nu 



50% Self-ab.H 



Intake Levels. Antimony is not an important naturally occurring 

 constituent of biological materials and has been of interest primarily on 

 account of its use as a chemotherapeutic agent against animal parasites. 

 It appears that absorption from the tract primarily depends on the sol- 

 ubility of the compound, but the toxicity of absorbed material depends 

 upon the oxidation state. It is considered that 1 to 5 ppm in food is 

 undesirable; 3 to 8 mg of tartar emetic (antimony potassium tartrate) in 

 man increases perspiration, 10 to 60 mg depresses the heart, 60 mg causes 

 vomiting, and 150 mg may cause death. Four milligrams of tartar 

 emetic has caused vomiting in dogs, and 50 mg/kg injected intravenously 

 into rats was fatal. 



Radioassay. Preparation Sb-124-P appears to be the one of choice, 

 presenting a compromise of relatively high specific activity, medium half- 

 life, and low radiocontamination. Sb^^^ offers a shorter half-life, but the 

 longer-lived Sb^-^ makes an increasing contribution with increasing age 

 of the sample. A mixture of Sb^-' and Sb^-^ can be used, provided that 

 a standard from the preparation administered to the organism is available 

 for decay corrections. However, it must be remembered that the self- 

 absorption characteristics may change as the composition of the mixture 

 changes with time. If a very high specific activity or a longer-lived iso- 

 tope is required, then preparation Sb-125-P may offer advantages. In 



