| Experiments | 1 | 2 | 3 | 4 |
| Acetic Acid | pH 4.0 | pH 4.0 | ----- | ----- |
| Citric Acid | ----- | ----- | pH 4.0 | 0.5 g/L |
| Setamol WS | ----- | 2.0 g/L | 2.0 g/L | ----- |