3.5. Preparation of Elution Solvent and Sample Solution

After acquiring the appropriate two-phase solvent system, the solvents was added into the separating funnel according to the volume ratio and mixed completely. The upper and lower phases were separated after stratification. The two phases were ultrasonically degassed in a water bath for 30 min (VCX750 Ultrasonic Cleaner, Sonics & Materials INC., Newtown, CT, USA) and utilized as the elution solvent. Crude extracts of different qualities (50, 60, 80, and 100 mg) were dissolved in the solvent system consisting of 5 mL upper phase and 5 mL lower phase to prepare sample solutions with different concentrations.