ml. l.OOON NaOH 



21.40 

 26.70 

 32.00 

 36.85 

 40.80 

 43.90 



CARBONATE-BICARBONATE BUFFERS 

 pH 9.4 - 10.4 



Reference: Determined in M.B.L. Chemical Room by J. D. Ostrow and 

 J. B. Russell, 1951. Data available on request. 



Stock Solution: 0.500M Sodium Bicarbonate 



Weigh accurately 21.0050 g. NaHCOg into a 500 ml. volumetric flask 



and dissolve to the mark with distilled water. Use Merck's reagent grade. 



The material may be used without drying if freshly opened in the dry room, 



but for more accuracy, dry at 110 C for four hours and store in a desiccator, 



Buffers : 



To make 250 ml. of O.IM Carbonate buffer, pipette 50ml. of the 0.500M 

 Bicarbonate stock solution into a 250 ml. volumetric flask, burette in the 

 volume of l.OOON NaOH indicated in the table below, and dilute to volume 

 with distilled water. 



pH ml. l.OOON NaOH pH ml, 



9.4 4.85 10.0 



9.6 7.63 10.2 



9.8 10.70 10.4 



l.OOON NaOH 



13.73 

 16.78 

 19.58 



HIGH-pH PHOSPHATE BUFFER 

 pH 11.0-12.0 



Reference: Biochem. Zeitschr. 189 191 (1927 ) ;Kolthof f and Vleeschhouwer 



Stock Solution: 0.500M Na2HP04 



Weigh out accurately 71.01 g. and dilute to 1 liter in a volumetric 

 flask. Freshly opened reagent grade chemicals may be used if kept in the 

 dry room. For greater accuracy, dry in an oven for two hours at 120 C. 



Bu f f e r s : 



To prepare 250 ml. of O.IM Phosphate buffer pipette 50 ml. of the 

 0.500M stock secondary phosphate solution into a 250 ml. volumetric flask, 

 add the volume of l.OOON NaOH indicated on the table below, and dilute to 

 the mark with distilled water. 



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