Table 1 Experimental parameters of extraction and purification steps, factor levels tested in the factorial design, and optimum values for SCCP determination
Factor | Low level | High level | Center | Optimum |
|---|---|---|---|---|
Sample amount (g) | 2 | 4 | 3 | 4 |
Extractant volume (mL) | 30 | 50 | 40 | 50 |
Boiling time (h) | 1 | 2 | 1.5 | 2 |
Rinsing time (h) | 0.5 | 1 | 0.75 | 1.5 |
Alumina amount (g) | 4 | 8 | 6 | 8 |
Acid silica amount (g) | 4 (30% H2SO4) | 8 (30% H2SO4) | 6 (30% H2SO4) | 4 (15% H2SO4) |
Elution volume (mL) | 80 | 130 | 105 | 50 |