Fig. 3. Separation of arylpropionic acids A1–A6 in ion exchange mode under HPLC conditions using the column-packed material IIa. Conditions: mobile phase, methanol/acetic acid/ammonium acetate (99/1/0.5, v/v/w%); flow rate of 1 ml min−1; temperature 20 °C. The injection volume was 5 μl with the sample concentration of 1 mg ml−1. The detection wavelength was set to 230 nm.
