Ultrasonic-assisted liquid–liquid extraction and HILIC–ELSD analysis of ginsenoside Rb1, astragaloside IV and dulcitol in sugar-free “Fufangfufangteng Heji”

A simple method for the extraction and determination of ginsenoside Rb1, astragaloside IV and dulcitol in sugar-free “Fufangfufangteng Heji” was developed using an ultrasonic-assisted liquid–liquid extraction (UALLE) coupled with Hydrophilic Interaction Liquid Interface Chromatography and Evaporative Light Scattering Detector (HILIC–ELSD) analysis. Good chromatographic separation was achieved using a Phenomenex Luna HILIC column (250 mm × 4.6 mm i.d., 5 μm), and a mobile phase consisting of acetonitrile–water at a flow rate of 1.0 ml/min with a gradient elution within 25 min was also used. Compared to the conventional analysis method, the proposed method had the advantages of a longer column life, shorter analysis time, lower baseline noise, short sample pretreatment time and low consumption of organic solvent. The linear ranges for ginsenoside Rb1, astragaloside IV and dulcitol were 0.0256–0.179, 0.110–0.770, 0.105–0.630 mg/ml, respectively. The recoveries of ginsenoside Rb1, astragaloside IV and dulcitol during the pharmaceutical preparation were within the range of 97.2–100.3%, and their relative standard deviations were 1.2–3.1%.