Table 1: SPE protocol optimization.
| Steps | Solvents | Percolated vol (mL) | |
|---|---|---|---|
| 1 | Conditioning | MeOH | 10 |
| aqueous H3PO4 (pH 2.5) | 5 | ||
| 2 | Loading | CBZ (5 mg L-1) | 1 |
| 3 | Aqueous washing | H2O or aq. EDTA solution (18.6 mg L-1) | 5 |
| 4 | Organic washing | ACN (100%) | 4 |
| or ACN/MeOH (98/2, v/v) | 2 | ||
| or ACN/MeOH (80/20, v/v) | 2 | ||
| or CH2Cl2 (100%) | 2 | ||
| 5 | Elution | CH2Cl2 /MeOH (80/20, v/v) MeOH | 5 |