Dissolution Characteristics, Zinc Stearate
| pH | Analyte Concentration, mg/L | ||||
|---|---|---|---|---|---|
| Prepared | Measured | Ca | Zn | Stearate | Palmitate |
| Low pH, 0.05 M sodium phosphate buffer, 0.15 g salt per100 mL of solution | |||||
| 2.5 | 3.0 | 0.14 | 291 | 0.11 | <0.05 |
| 3.0 | 4.4 | 0.20 | 137 | <0.05 | <0.05 |
| 3.5 | 4.9 | <0.05 | 19.3 | 0.06 | <0.05 |
| 4.0 | 5.3 | <0.05 | 6.6 | <0.05 | <0.05 |
| 4.5 | 5.5 | <0.05 | 3.8 | <0.05 | <0.05 |
| Intermediate pH, 0.05 M potassium phosphate buffer, 0.15 g salt per 100 mL of solution | |||||
| 5.0 | 5.5 | 0.70 | 4.3 | 0.05 | <0.05 |
| 5.5 | 5.8 | 0.76 | 2.8 | 0.05 | <0.05 |
| 6.0 | 6.1 | 0.59 | 1.9 | <0.05 | <0.05 |
| 6.5 | 6.5 | 0.57 | 0.50 | <0.05 | <0.05 |
| 7.0 | 7.0 | 0.27 | 1.0 | <0.05 | <0.05 |
| 7.5 | 7.5 | 0.26 | 0.33 | <0.05 | <0.05 |
| High pH, 0.025 M borate (sodium borate decihydrate) buffer, 0.5 g salt per 100 mL of solution | |||||
| 8.0 | 8.1 | 0.18 | 0.41 | <0.05 | <0.05 |
| 8.5 | 8.6 | 0.22 | 0.07 | 0.05 | <0.05 |
| 9.0 | 9.0 | 0.35 | 0.08 | <0.05 | <0.05 |
| 9.5 | 9.4 | 0.17 | 0.02 | 0.13 | 0.10 |
| 10.0 | 9.9 | 0.12 | 0.04 | 0.68 | 0.28 |
| 10.5 | 10.3 | 0.07 | 0.05 | 1.85 | 0.94 |
| 11.0 | 10.6 | 0.09 | 0.05 | 1.30 | 0.97 |