Extraction of glabridin and glycyrrhizic acid from Licorice by Ultrasound assisted-Cloud point extraction and their determination by HPLC

An analytical method was applied for the extraction and determination of Glabridin and Glycyrrhizic acid, two important compounds of licorice, by ultrasound-assisted cloud point extraction and HPLC. Non-ionic surfactant Triton X-100, an environmentally friend solvent, was used for cloud point extraction of these compounds. Effective parameters on extraction recovery, such as the concentration of surfactant, salt concentration, the pH of the sample solution and ultrasound-assisted extraction time were investigated and optimized. The optimum conditions for extraction of glabridin and glycyrrhizic acid were 5% v/v concentration of Triton X-100 in the presence of 0.015 g/mL NaCl at pH=3 with 5min ultrasound time. At optimized conditions, limits of detection were 0.017 µg/mL for glabridin and 0.024 µg/mL for glycyrrhizic acid with linear ranges of 5-120 µg/mL and 10 -200 µg/mL, respectively. Recovery percentages were 88.8% for glabridin and 86.4% for glycyrrhizic acid with RSDs% of 1.4% and 1.8% respectively.

Keywords:

Glabridin , Glycyrrhizic acid , Ultrasound-assisted cloud point extraction , HPLC