416 Solution Preparation (sec. 1) 



pH M/5 acetic acid M/5 sodium acetate 



0.05M Barbital Buffer (gomori) (pH 8.7-6.9) 



STOCK solutions: 



sodium barbital: 1.03 gm. in 50 ml. distilled water 



Add O.IN HCl according to table below and dilute to total of 100 ml.: 



Boric Acid-borax Buffer (holmes) (pH 7.4-9.0) 



STOCK solutions: 



M/5 boric acid: 12.368 gm. made up to 1000 ml. witti distilled water 

 M/20 borax: 19.071 gm. made up to "^OOO ml. with distilled water 



For desired pH mix correct amoiuits as i^idicated below: 



