214 BISMUTH 



Bismuth 210 (5.02 days) Beta 1.17 Gamma 



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



Bi-210-I 0.4 mc/g Metal $14/10 mc — Po^io daughter (138.3 days) 



I[rica W. Int. C. Scint. C. 50% Self-abs. 



1.0 X 10-4 7 6 X 10-5 4 8 X 10-= 72 (calc.) 



Intake Levels. Bismuth does not occur naturally to any significant 

 extent in biological materials; it is used as a drug. Bi-^" was employed 

 in early work for studies of blood flow. However, other radioisotopes, 

 particularly of sodium, are now preferred for this purpose. Bismuth is 

 relatively nontoxic. Continued dosage of 5 to 10 mg/kg daily produced 

 kidney lesions in rabbits, and 40 to 50 mg/kg was tolerated when injected 

 intramuscularly, although larger doses may cause kidney damage (Bi-1). 

 About 20 mg/kg of sodium bismuthate injected intravenously was fatal 

 for rats. 



Radioassay. The contribution of Po'-^° daughter, which emits 5.3-Mev 

 alpha particles and 0.77-Mev gamma rays, can be minimized by measure- 

 ment so that the alpha particles are absorbed and the bismuth beta par- 

 ticles are efficiently counted. 



Chemistry. A method for estimation of bismuth in biological materials 

 consists in wet oxidation; addition of a small amount of copper and 

 precipitation of bismuth, lead, and copper as the sulfides, which are then 

 dissolved in HNO3, brought to pH 9.5, and extracted with dithizone in 

 chloroform in the presence of enough cyanide to retain the copper. The 

 lead and bismuth are liberated from the dithizone, and their nitrates 

 brought to pH 2 for another extraction with dithizone; this extracts the 

 bismuth, which can be determined colorimetrically (Bi-1). 



Typical Methods. References (Bi-2, Bi-3) describe, for historical 

 interest, the use of this radioisotope for determination of blood-flow char- 

 acteristics in human beings. 



Bi-1. Monier-Williams, G. W.: "Trace Elements in Food," John Wiley & Sons, Inc., 



New York, 1950. 

 Bi-2. Blumgart, Herrmann, and Otto C. Yens: Studies on the Velocity of Blood 



Flow. I. The Method Utilized, J. Clin. Invest., 4: 1-13 (1927). 

 Bi-3. Blumgart, Herrmann L., and Soma Weiss: Studies on the Velocity of Blood 



Flow. II. The Velocity of Blood Flow in Normal Resting Individuals and a 



Critique of the Method Used, J. Clin. Invest., 4: 15-31 (1927). 



