HPLC analysis of glycyrrhizin and licochalcone a in Glycyrrhiza inflata from Xinjiang (China)

Abstract

Various methods have been published for the analysis of these compounds in licorice, including high-performance liquid chromatography (HPLC) [14–17], high-performance thin-layer chromatography (HPTLC) [18], and capillary electrophoresis [19, 20]. However, these published methods mainly involve Glycyrrhiza glabra and G. uralensis [21–22]. There are few special studies reported on the analysis of Glycyrrhiza inflata. Based on the above-mentioned purpose, the aim of the current study was to develop a simple reversed-phase highperformance liquid chromatography (HPLC) method for simultaneous quantification of glycyrrhizin and licochalcone A. In order to validate the HPLC quantitative method, the specificity, linearity, accuracy, precision, and limits of detection and quantification of the method were investigated. The specific content of these compounds in eight samples using our technique was also examined. Each of the six standards for glycyrrhizin, liquiritin, and licochalcone A was analyzed in three replicates. Table 1 shows the results. The calibration curve was constructed by plotting the peak area against the concentration (g/mL) using linear regression analysis. The relative standard deviation (RSD) values of the peak areas of three replicate injections were between 1.52 and 3.29%. Dilute solutions of the reference compounds were further diluted to a series of concentrations with methanol to assess the limits of detection (LOD) and quantification (LOQ). The LOD and LOQ under the present chromatographic conditions were determined at a signal-to-noise (S/N) ratio of 3 and 10, respectively.The LOD values for glycyrrhizin and licochalcone A were 4.2 ng and 3.3 ng. The LOQ values were 14.3 ng and 10.5 ng, respectively.