Development of sample preparation method for isoliquiritigenin, liquiritin, and glycyrrhizic acid analysis in licorice by ionic liquids-ultrasound based extraction and high-performance liquid chromatography detection

► Licorice components were first extracted by ionic liquid based method. ► The efficiency in this work is higher than that of the conventional solvent method. ► The proposed approach was confirmed by good recovery and reproducibility. ► The proposed approach has eco-friendly, convenient, high practical value technique.