Ultrasound-assisted dispersive liquid-liquid microextraction method combined with HPLC-fluorescence detection for the determination of glycyrrhetinic acid in liquorice and liquorice-derived food products
J IRAN CHEM SOC Journal of the Iranian Chemical Society
Format: Journal Article
Publication Year: 2016
Pages: 359 - 367
Source ID: shanti-sources-105046
Collection: Himalayan and Tibetan Medicine
Abstract: A sensitive and inexpensive method involving ultrasound-assisted dispersive liquid-liquid microextraction (UA-DLLME) and pre-column derivatization followed by high-performance liquid chromatography with fluorescence detection (HPLC-FLD) was developed for the analysis of glycyrrhetinic acid. In this work, glycyrrhetinic acid could be obtained by hydrolyzing glycyrrhizic acid to remove glucuronic acid and subsequently extracted by UA-DLLME using chloroform and acetone as the extraction and disperser solvents, respectively. The sample extraction was firstly concentrated to dry under nitrogen and then rapidly derivatized with 2-(12-oxobenzo[b]acridin-5(12H)-yl)-ethyl-4-toluenesulfonate (BAETS) after the UA-DLLME. The prime parameters influencing the UA-DLLME and derivatization procedure were optimized using response surface methodology. Under the optimum conditions, the proposed method has a better linearity in a wider range of 6-300 ng mL−1 and a high square of correlation coefficient (R 2) at 0.9994. Limit of detection and limit of quantification were found to be 1.7 ng mL−1 and 5.8 ng mL−1, respectively. The proposed method was applied to the analysis of glycyrrhetinic acid in liquorice, liquorice apricot and sugar plum samples. For the analysis of the spiked samples, the spiked recoveries were in the range of 90.4-103.0 % with RSD less than 5.18 %. All results demonstrated that the UA-DLLME-HPLC-FLD (ultrasound-assisted dispersive liquid-liquid microextraction-high-performance liquid chromatography with fluorescence detection) was a sensitive, accurate, efficient analytical method for the determination of glycyrrhetinic acid.