452 



THIAMINE 



tions of normal young men on controlled intakes of thiamine from up to 

 16 mg. per day, found that at intake levels between 0.7 and 1 mg. of thia- 

 mine per day the thiamine excretion may be used as an indicator of the 



TABLE IV 



Collaborative Results by the Recommended Thiochrome Method 



Table V 

 Results by Biological and Microbiological Methods 



Laboratory Method used 



Thiamine found, 7/g. 



Wheat 



Dried yeast 



Malt Wheat flour Yeast Sample Sample Sample 

 extract germ (85%) extract 12 3 



3.3 



58 



45 

 27 



38 



17 



54 



Mean value of the collaborative fluori- 

 metric results (from Table IV) 



3.62 21.3 3.75 51.3 29.1 16.8 50 



intake. From 1 mg. up to about 5 mg., however, it is better to use the pyra- 

 mine excretion. Pyramine is the pyrimidine-like component of the thia- 

 mine molecule which is excreted in the urine. The pyramine content of the 

 urine was determined by a modification of the yeast fermentation method 

 of Schultz ei al}'^ The standard used in these determinations was 2-methyl- 

 4-amino-5-ethoxymethylpyrimidine hydrochloride. 



