Dissolution Characteristics, Calcium Stearate
| pH | Analyte Concentration, mg/L | ||||
|---|---|---|---|---|---|
| Prepared | Measured | Ca | Zn | Stearate | Palmitate |
| Low pH, 0.05 M sodium phosphate buffer, 0.15 g salt per 100 mL of solution | |||||
| 2.5 | 3.0 | 166 | <0.01 | <0.05 | <0.05 |
| 3.0 | 5.3 | 124 | <0.01 | 0.20 | 0.09 |
| 3.5 | 5.6 | 70 | <0.01 | 0.30 | 0.13 |
| 4.0 | 5.7 | 57 | <0.01 | 0.36 | 0.16 |
| 4.5 | 5.8 | 53 | <0.01 | 0.37 | 0.17 |
| Intermediate pH, 0.05 M potassium phosphate buffer, 0.15 gram salt per 100 mL of solution | |||||
| 5.0 | 5.8 | 50 | 0.03 | 0.19 | 0.05 |
| 5.5 | 5.9 | 41 | 0.02 | 0.18 | 0.06 |
| 6.0 | 6.1 | 22 | 0.01 | 0.07 | <0.05 |
| 6.5 | 6.5 | 7.8 | 0.01 | 0.32 | 0.13 |
| 7.0 | 7.0 | 7.5 | 0.01 | 0.25 | 0.11 |
| 7.5 | 7.5 | 5.2 | 0.01 | 0.15 | 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 | 5.1 | <0.02 | 0.36 | 0.02 |
| 8.5 | 8.6 | 5.4 | <0.01 | 0.30 | 0.07 |
| 9.0 | 9.0 | 5.8 | 0.08 | 0.57 | 0.21 |
| 9.5 | 9.4 | 5.3 | <0.01 | 0.51 | 0.29 |
| 10.0 | 9.9 | 4.6 | 0.03 | 0.48 | 0.41 |
| 10.5 | 10.2 | 5.2 | <0.01 | 0.50 | 0.27 |
| 11.0 | 10.5 | 4.5 | <0.01 | 0.24 | <0.05 |