Excretion of Creatine in Carbohydrate Starvation. 215 



bath is sufficient to estimate accurately small amounts of creatine up to 

 O034 grm. per 100 c.c., but that a greater quantity than this cannot be 

 converted quantitatively into creatinine in three and a half hours. Larger 

 amounts than - 034 grm. per 100 c.c. must be heated for more than three 

 and a half hours, and it is very difficult, even so, to convert all the creatine 

 into creatinine. As the greatest amount of creatine found by Cathcart(5) 

 in a case of carbohydrate starvation was 0-38 grm. per day, three and a half 

 hours' heating on a water-bath would be quite sufficient to convert prac- 

 tically all the creatine, that might be present in the urine, into creatinine. 



Finally, to test the accuracy of the distillation method, we have employed 

 it for urines containing both creatine and aceto-acetic acid in solution 

 together (Table VI). In one experiment creatine was added to normal 

 urine, and the estimations were carried out with and without the addition of 

 aceto-acetic acid. In the second experiment the creatine was added to part 

 of the urine of the third day of the diet experiment (Table VIII). In this 

 case the urine already contained aceto-acetic acid. The results (Table VI) 

 show that, even when both aceto-acetic acid and creatine are present at the 

 same time, the aceto-acetic acid can be removed from the urine without 

 breaking up the creatine, and that the creatine, if present in small amount, 

 can be converted almost quantitatively into creatinine after three and a half 

 hours' heating. The series of control experiments shows that the distillation 

 method gives satisfactory results. 



Table VI shows the Accuracy of the Distillation Method for Urines 

 containing both Creatine and Aceto-acetic Acid. 







Creatinine. 



Creatinine 

 + creatine 

 (as 



creatinine), 

 Folin's 

 method. 



Creatine 

 recovered 

 by experi- 

 ment (as 

 creatinine). 



Percentage 

 recovered. 







Folin's 

 method. 



Distillation 

 method. 



A 



Normal urine + creatine 

 01 grm. per 100 c.c. 



Same urine + creatine 

 O'Ol grm. per 100 c.c. 

 + 0'0tj grm. of aceto- 

 acetic acid per 100 c.c. 



grm. per 

 100 c.c. 

 0-071 



0-047 



grm per 

 100 c.c. 

 0-070 



0-070 



grm. per 

 100 c.c. 

 -080 



0-079 



grm. per 

 100 c.c. 

 01 



-009 



100 

 90 



B 



Urine of Day 3, Experi- 

 ment II, containing 

 0'112 grm. of aceto- 

 acetic acid per 100 c.c. 



Same urioe + creatine 

 0'04 grm. per 100 c.c. 



o-io 



0*10 



0-119 

 0-120 



0-119 

 0-156 







0-036 



90 



