140 



Scientific Proceedings (ioo). 



79 (i454) 



Determination of carbon monoxide in blood. 

 By Donald D. Van Slyke and Harold A. Salve sen. 



[From the Hospital of The Rockefeller Institute for Medical Research, 



New York.] 



The blood is treated as in the determination of oxygen by Van 

 Slyke's method. 1 A mixture of gases consisting of oxygen, 

 carbon monoxide and the slight amount of nitrogen gas held in 

 solution in the blood, is obtained. The extraction of the gases 

 must be continued for a somewhat longer time than the one 

 minute which is sufficient when oxygen alone is bound by the 

 hemoglobin, otherwise the technique is the same. After the 

 gases are measured, the oxygen is absorbed by permitting 1 or 2 

 c.c. of alkaline pyrogallol solution to flow slowly into the chamber 

 of the apparatus from the cup at the top. The residual gas, 

 corrected for the 0.009 c - c - of nitrogen gas per c.c. of blood known 

 to be present, is the carbon monoxide. 



80 (1455) 

 Titration of organic acids in urine. 



By Donald D. Van Slyke and Walter W. Palmer. 



[From the Hospital of The Rockefeller Institute for Medical Research, 



New York.] 



Carbonates and phosphates are removed by adding 2 grams 

 of calcium hydroxide to 100 c.c. of urine, and filtering after 10 

 minutes. 25 c.c. of the filtrate is brought to a pH of approximately 

 8 by adding 0.2 N HC1 with phenolphthalein as indicator, till the 

 pink color disappears. Then 5 c.c. of 0.02 per cent. Tropeolin 00 

 solution are added, and the solution is titrated to a pH of 2.7 

 with 0.2 N HC1, the volume being brought to approximately 

 50 c.c. by addition of water towards the end of the titration. The 

 color is compared with that of 50 c.c. of a control solution with 



Jour. Biol. Client., 1918, xxxiii., p. 127. 



