2.4. Chromatographic conditions
Analysis was performed using an Agilent 1260 Series LC system equipped with UV-detector and a Zorbax Eclipse Plus C18 column (4.6 mm × 250 mm). The chromatogram was recorded at 285 nm and the peak areas were quantified. The mobile phase was ACN/H2O (70:30, v/v) and maintained at 1.0 mL min−1. Sample injection volume was 10 μL and column thermostat temperature was 25 °C.
2.5. Preparation of standard solutions
Stock solution of metrafenone (1000 μg/mL) was prepared by dissolving 25.08 mg of metrafenone in 25 mL acetonitrile. Working solution was prepared by further dilution the stock solution in acetonitrile to 0.05, 0.4, 1.0, 5.0, 10.0 and 50.0 μg/mL.
3. Results and discussion