Comparison between the developed HPLC method and the reported ones.
| Methods | Developed HPLC method | Reported method for DFX | Reported method for DFP |
|---|---|---|---|
| Linearity range (μg mL−1) | 0.3–20 for DFX | 0.4–80 | 0.25–10 |
| 0.2–20 for DFP | |||
| Mobile phase | Ethanol : acidic water at pH 3.0 adjusted by phosphoric acid in the ratio of (70 : 30, by volume) | 50 mM ammonium acetate and 20 mM tetrabutylammonium hydrogen sulfate buffer (pH 6.3) : acetonitrile : methanol (33 : 22 : 45, by volume) | Methanol : potassium phosphate buffer (50 mM) containing heptane sulfonic acid (5 mM) adjusted the pH = 3.5 ± 0.05 with phosphoric acid (18 : 82, by volume) |
| Stationary phase | XBridge® HPLC RP-C18 (4.6 × 250 mm, 5 μm) | PEEK-lined ProteCol-P C18 HQ105-coated column (4.6 × 250 mm, 5 μm) | Discovery supelco C18 column (4.6 × 250 mm, 5 μm) |
| Run time (min) | 6 | 8 | 12 |
| Flow rate (mL min−1) | 1 | 1 | 1.2 |
| Solvent wastea (g per run) | 6 | 8 | 14.4 |
| Wavelength (nm) | 225 | 225 | 280 |
a
Solvent waste: (run time × flow rate).