Table 1 The HPLC–DAD gradient elution program
Time (min) | 20.0 mM potassium dihydrogen phosphate solution, pH 3.0 ± 0.2 (%) | Acetonitrile (%) | Flow rate (mL/min) |
|---|---|---|---|
0.00 | 90.0 | 10.0 | 1.0 |
3.00 | 90.0 | 10.0 | 1.0 |
10.00 | 50.0 | 50.0 | 1.0 |
10.01 | 20.0 | 80.0 | 1.5 |
20.00 | 20.0 | 80.0 | 1.5 |
20.10 | 90.0 | 10.0 | 1.5 |
25.00 | 90.0 | 10.0 | 1.5 |