HEMOGLOBIN DETERMINATION 207 



about a dozen times, so that the hemoglobin becomes thoroughly 

 saturated with CO and the full pink tint of CO-hemoglobin 

 appears. Water is then added drop by drop from the dropping 

 pipette supplied, until the point is reached when the tints appear 

 to be equal. The percentage is read off on the tube after one- 

 half minute has been allowed for the liquid to run down. Another 

 drop is now added, and if necessary, another, until the tints again 

 appear unequal. The mean of the readings which gave equality 

 is taken as the correct result. 



In comparing the tints of the two tubes, it is best to hold them 

 up against the light from the sky, or toward an opal glass globe 

 when artificial light is used. The precaution must always be taken 

 of repeatedly transposing the tubes from side to side during the 

 observations; otherwise very considerable errors may arise. 



The error of the method is not greater than 1 per cent. 



Preparation of Standard CO-Hemoglobin. The standard solu- 

 tion for the hemoglobinometer is a 1 per cent solution, saturated 

 with coal gas, of ox or sheep blood of the average oxygen capacity 

 of normal adult males (18.5 per cent). In making the standard 

 solution the tube should be sealed and no air should be in the 

 tube, otherwise the standard will gradually change its tint. 



HEMOGLOBIN DETERMINATION 



Palmer's Method l 



Principle. Hemoglobin of the blood is transformed into CO- 

 hemoglobin and comparison is then made in the colorimeter with 

 a standard solution of CO-hemoglobin. 



Procedure. Fill a 10 c.c. volumetric flask about half full of 

 the dilute ammonia (see below). Draw blood to the mark in the 

 0.1 c.c. pipette. Transfer to the volumetric flask containing the 

 ammonia water, drawing the solution into the pipette two or three 

 times to wash out all blood. Next fill the volumetric flask to the 

 mark with the ammonia solution. Transfer contents to a large- 

 sized test-tube and bubble briskly illuminating gas or carbon 

 monoxide through the hemoglobin solution for at least thirty 

 seconds (this operation should, of course, be carried out in a hood 



1 Palmer: Jour. Biol. Chem., 1918, 33, 119. 



