TABLE 2.
Chemical composition of the buffer systems, and pH and electric conductivity (EC) of the control and NaCl solutions.
| pH | Buffer system | Protocol for the preparation of buffer solutions |
0 mM NaCl |
100 mM NaCl |
150 mM NaCl |
200 mM NaCl |
||||
| pH | EC (mS cm–1) | pH | EC (mS cm–1) | pH | EC (mS cm–1) | pH | EC (mS cm–1) | |||
| 7.1 | Tris-HCl buffer | 50 mL 0.1 M Tris solution mixed with 45.7 mL 0.1 M HCl, and diluted to 100 mL with Milli-Q water | 7.5 | 3.5 | 7.6 | 12.2 | 7.6 | 16.4 | 7.6 | 20.6 |
| 8.0 | 50 mL 0.1 M Tris solution mixed with 29.2 mL 0.1 M HCl, and diluted 100 mL with Milli-Q water | 8.2 | 2.3 | 8.2 | 11.3 | 8.3 | 15.7 | 8.3 | 19.7 | |
| 9.0 | 50 mL 0.1 M Tris solutions mixed with 5.7 mL 0.1 M HCl, and diluted to 100 mL with Milli-Q water | 9.2 | 0.5 | 9.2 | 9.8 | 9.3 | 14.1 | 9.3 | 18.4 | |
| 10.0 | NaHCO3-NaOH buffer | 50 mL 0.05 M NaHCO3 mixed with 10.7 mL 0.1 M NaOH, and diluted to 100 ML with Milli-Q water | 10.0 | 2.9 | 9.8 | 11.8 | 9.7 | 16.0 | 9.6 | 20.2 |
| 11.0 | 50 mL 0.05 M NaHCO3 mixed with 22.7 mL 0.1 M NaOH, and diluted to 100 ML with Milli-Q water | 10.8 | 4.0 | 10.6 | 12.7 | 10.6 | 16.8 | 10.5 | 20.1 | |