652 



ADVENTURES IN EADIOISOTOPE KESEARCH 



of carrier iron as FeClg to bring up the iron content of the sample to 

 a total amount of 500 microgram, (c) precipitation of the solution with 

 HgS after neutralizing it with ammonia, (d) collection of the FeS obtained 

 on a filter paper placed on the bottom of a perforated aluminum dish of 

 1.2 cm diameter and 2 mm depth (as used in the determination of the 

 radioactivity of ammonium magnesium phosphate precipitates), (e) plac- 



Table 2. — Serum from Human Subjects Previ- 

 ously Injected with Serum Containing ^^Fe 1 ml, 

 Serum was Dried at 100° C, Wet ashed with 1 ml 

 Sulfuric Acid and Some Perhydrol and its 

 Activity Determined as described 



Table 3. — Determination of ^^Fe 



content of Hemin isolated from 

 Human Erythrocytes. Combustion 

 AS Stated in Table 2, iron Deter- 

 mined Colorimetrically With 

 Sulfosalicylic Acid 



