GAS ANALYSIS 



327 



ing, until a dark red solution is obtained. The full tube is closed, 

 taking care to exclude air bubbles, shaken, and finally stored in a 

 syringe with a bubble of nitrogen.) Each syringe is connected by 

 stiff rubber tubing to a drawn-out glass tube. The orifice of the glass 



wmm 



\ 



i 



Fig. 102. Steps in the 

 introduction of the sample 

 into the 10 fil. gas analyzer. 

 From Scholander (1942h) 



Fig. 101. Analyzer for 10 lA. of gas mixture. 

 From Scholander (1942h) 



tip should not be fine enough to cause pressure to develop in the 

 syringe" during delivery, since this would force air or nitrogen into 

 solution and result in low absorption values. A glass tip connected 

 to suction is also required. Syringe needles, if not finer than 20 

 gage, may be substituted for the glass tips. 



The transfer pipette (Fig. 102) is convenient for handhng the gas 

 sample {&). It consists of 2-2.5 mm. bore glass tube drawn out at 

 one end and connected to a piece of rubber tubing at the other. One 

 end of the rubber tube is plugged with a piece of glass rod. Mercury 

 is used to confine the sample as in ^. A transparent cap with a cen- 

 tral hole fits over the absorption chamber to guide the tip of the 

 pipette. 



Manipulation. As an example of the procedure to be followed, 

 consider the analysis of a mixture of carbon dioxide, oxygen, and 

 nitrogen : 



1. Rinse the absorption chamber and bulb with 0.5 N sulfuric 

 acid and move the mercury up to the absorption chamber. 



