I 



POTASSIUM CHLORIDE BUFFER: pH 1.0 - 2.2 



Ref: Clark and Lubs: J. Biol. Chem; 2S 479 (1916) 



Stock Solution: l.OOOM Potassium Chloride 



Prepared by dissolving 14.912 g. of KCl in enough distilled water to 

 make 200 ml. of solution. Merck's Reagent may be used directly if freshly 

 opened in the dry room and kept there. For greater accuracy, dry four 

 hours at 120*'C. 



Buffers : 



To make 200 ml. of 0.05 M (1/20 M) buffer, pipette 10 ml. of the 

 1.000 M stock solution into a 200 ml. volumetric flask, add the volume 

 standard (l.OOOM or 0. lOOOM as specified) HCl listed below, and dilute 

 to the mark with distilled water. 



pH ml. O.IOOOM HCl 



1.8 32.20 



2.0 21.20 



2.2 13.40 



POTASSIUM HYDROGEN PHTHALATE BUFFERS 



With HCl: pH 2.2 - 3.8 With NaOH: pH 4.0 - 6.2 



Ref: Clark and Lubs: J. Biol. Chem. ^ 479 (1916) 

 Stock Solution : 0.200M Potassium Biphthalate 



Prepared by dissolving 40.828 g. of Merck's Reagent Potassium 

 Biphthalate in enough distilled water to make 1 liter. The Merck 

 product may be used directly if opened and kept in the dry room. For 

 greater accuracy, dry for several hours at 110 -120 C 



Buffers : 



To prepare 200 ml. of 0.05 M Phthalate buffer, pipette 50 ml. of 

 the stock 0.200M solution into a 200 ml. volumetric flask, add the spec- 

 ified amount of the standard HCl or NaOH (l.OOOM or O.IOOOM as listed) 

 and dilute to the mark with distilled water. 



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