Preparation of 0.1M Sodium Phosphate Buffer of Desired pH

Sodium Phosphate Buffer has a buffering range between 5.8 – 8.0. By mixing monobasic (NaH2PO4) and dibasic (Na2HPO4) sodium phosphate solutions in the right proportion, you can prepare a sodium phosphate buffer of a desired pH. 

To prepare 1000 ml of 0.1M Sodium Phosphate Buffer of desired pH, mix 1M sodium phosphate monobasic (NaH2PO4), 1M sodium phosphate dibasic (Na2HPO4), and water as suggested in the following table.

Preparation of 1L of 1M Sodium phosphate buffer of the desired pH
Final pH of the solution
(Final volume: 1000 ml)
Volume of 1 M NaH2PO4 Volume (mL) of 1 M Na2HPO4Water
5.892 ml8 ml900 ml
5.990 ml10 ml900 ml
6.087.7 ml12.3 ml900 ml
6.185 ml15 ml900 ml
6.281.5 ml18.5 ml900 ml
6.377.5 ml22.5 ml900 ml
6.473.5 ml26.5 ml900 ml
6.568.5 ml31.5 ml900 ml
6.662.5 ml37.5 ml900 ml
6.756.5 ml43.5 ml900 ml
6.851 ml49 ml900 ml
6.945 ml55 ml900 ml
7.039 ml61 ml900 ml
7.133 ml67 ml900 ml
7.2 *28 ml72 ml900 ml
7.323 ml77 ml900 ml
7.419 ml81 ml900 ml
7.516 ml84 ml900 ml
7.613 ml87 ml900 ml
7.710.5 ml89.5 ml900 ml
7.88.5 ml91.5 ml900 ml
7.96.7 ml93.3 ml900 ml
8.05.3 ml94.7 ml900 ml
* To prepare 1000 ml solution of 1M Sodium phosphate buffer of pH 7.2, mix 28 ml of 1M Sodium phosphate monobasic, 72 ml of Sodium Phosphate dibasic and 900 ml of water. 

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