[Determination of pinoresinol diglucoside in Qing' e Pills by ultra performance liquid chromatography]

A new ultra performance liquid chromatographic (UPLC) method was established for the determination of pinoresinol diglucoside (PDG) in Qing' e Pills. After extracted by the Soxhlet's method, the methanol extracts of the samples were passed through a Waters Oasis HLB SPE column to achieve good chromatographic performance. The separation was performed on a Waters Acquity C18 BEH column (100 mm x 1.0 mm, 1.7 microm) with acetonitrile-water (the pH adjusted to 4.0 with phosphoric acid) (9: 91, v/v) as the mobile phase at a flow rate of 0.1 mL/min. The detection wavelength was set at 227 nm, the column temperature was 25 degrees C and the injection volume was 0.5 microL. Under the optimized conditions, there was good linear relationship between the mass concentration and the peak area of PDG in the range of 1.40 - 506.00 mg/L with the correlation coefficient of 1. The average recoveries of PDG at three levels ranged from 100.10% to 102.37%. The method is accurate, sensitive, highly reproducible and suitable for the quality control of Qing' e Pills.