BLOOD GAS ANALYSIS 



119 



BLOOD GAS ANALYSIS 



Method of Henderson and Smith l 



Principle. Modification of the 

 Haldane. The apparatus used con- 

 sists of the Haldane gas analyzer in 

 either its original or modified form 

 and a special small graduated diffu- 

 sion tube. 



Solutions Employed. (1) Dilute 

 ammonia (1 c.c. of concentrated 

 ammonia in 500 c.c. of distilled 

 water) kept tightly stoppered to 

 avoid absorption of CO2 from the 

 air (or freed from carbonate with 

 barium hydroxide and ammonium 

 sulphate). A little saponin is dis- 

 solved in the ammonia solution 

 when an oxalate is used to prevent 

 the blood sample from clotting. 

 (2) A 10 per cent solution of potas- 

 sium ferricyanide. (3) A 20 per 

 cent solution of tartaric add. 



OXYGEN ANALYSIS 



Procedure. The stop-cock of 

 the diffusion tube is closed (i.e., 

 turned to connect the side and end 

 nipples); 1.5 c.c. of the ammonia 

 solution are placed in the tube; and 

 1 c.c. of the blood to be analyzed 

 is introduced below the ammonia 

 by means of a pipette. A short 

 close-fitting rubber stopper is in- 

 serted in the large end. An hypo- 

 dermic needle (disconnected from 

 its syringe) is passed through this 



method of Barcroft and 



FIG. 5 The Blood Gas Dif- 

 fusion Tube. The plug of the 

 stop-cock is bored only in a 

 right angle, not in a T, so that 

 only two of the openings are 

 connected at once. The open 

 end of the tube is graduated as 

 shown. This end of the tube 

 is closed with a rubber stopper 

 cut to about a half or a third 

 the usual length, so that the 

 needle of a small all glass 

 hypodermic syringe can be 

 thrust through it. (Jour. Biol. 

 Chem., 1918, 33, 40.) 



Henderson and Smith: Jour. Biol. Chem., 1918, 33, 39. 



