Potassium phosphate

1 M Potassium phosphate buffer

To make 100 mL of 1M potassium phosphate:

pH mL 1M K2HPO4 mL KH2PO4 (mL)
5.8 8.5 91.5
6.0 13.2 86.8
6.2 19.2 80.8
6.4 27.8 72.2
6.6 38.1 61.9
6.8 49.7 50.3
7.0 61.5 38.5
7.2 71.7 28.3
7.4 80.2 19.8
7.6 86.6 13.4
7.8 90.8 9.2
8.0 94.0 6.0

from http://ivaan.com/protocols/151.html

To make approximately: mL Potassium phosphate buffer
with: pH
start with approximately: mL K2 (base)
and: mL K1 (acid)

Check the pH with the meter.

Add more K2 to raise the pH, or K1 to lower it.

Dilute as necessary to achieve the desired concentration.