Deep Eutectic Solvent-Based Microwave-Assisted Extraction for the Chromatographic Analysis of Bioactive Flavonoids in Spirodela polyrrhiza.

Abstract

Deep eutectic solvents (DESs) are regarded as promising solvents to extract chemicals from plant materials. In this study, a DES-based microwave-assisted extraction (MAE) method was developed for the chromatographic analysis of four bioactive flavonoids in Spirodela polyrrhiza. Chromatographic separation was achieved on a Promosil C18-column. Prior to the HPLC analysis, the flavonoids were rapidly extracted by a DES-MAE process using choline chloride/levulinic acid (1:2, mol/mol) as the solvent. The extraction parameters were optimized using response surface methodology, and the optimal DES-MAE was fast and efficient compared with conventional solvent-based MAE and ultrasonic-assisted extraction using DES. The recoveries of optimized DES-MAE for the four flavonoids ranged from 97.80 to 103.29%. This study demonstrates that the validated DES-MAE-HPLC method is efficient, accurate and applicable to the determination of flavonoids in S. polyrrhiza.