Table 1.
Summary of binding constants for multicarboxylic acids used in this study, their net charge at pH 8.5, induction time, and pH at induction
| Carboxylic acid | Binding constant* |
Net charge | Induction |
|||
|---|---|---|---|---|---|---|
| log(KCa2+) | log(KMg2+) | log(KCa2+/KMg2+) | Time, min | pH | ||
| C4H6O5 (oxydiacetic acid) | 3.38 | 1.8 | −1.58 | −2 | 136 | 9.79 |
| C4H6O6 (d-tartaric acid) | 1.8 | 1.36 | −0.44 | −2 | 66.5 | 9.37 |
| C6H8O7 (citric acid) | 3.5 | 3.37 | −0.13 | −3 | 114.5 | 9.58 |
| C5H9O4N (glutamic acid) | 1.43 | 1.9 | 0.47 | −1.7 | 50 | 9.8 |
| C3H4O4 (malonic acid) | 1.51 | 2.11 | 0.6 | −2 | 88.5 | 9.66 |
| C4H7O4N (aspartic acid) | 1.6 | 2.43 | 0.83 | −1.7 | 68 | 9.8 |
| HCO3− (hydrogen carbonate) | 1 | 0.95 | −0.05 | −1 | ||
| CO32− (carbonate) | 3.15 | 2.88 | −0.27 | −2 | 40.5 | 10.34 |
*Binding constant K for the generalized association reaction: M + L ⇄ ML, with M representing the metal and L the ligand (52).