| Comparison | Pseudo-F | P-value |
| pH 6 vs pH 7 | 1.86 | 0.04 |
| pH 6 vs pH 9 | 17.15 | 0.01 |
| pH 6 vs pH 10 | 25.46 | 0.01 |
| pH 7 vs pH 9 | 15.27 | 0.01 |
| pH 7 vs pH 10 | 22.31 | 0.01 |
| pH 9 vs pH 10 | 1.62 | 0.03 |