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.

中文翻译：

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深共晶溶剂微波辅助萃取多根螺旋藻生物活性黄酮的色谱分析

低共熔溶剂（DES）被认为是从植物材料中提取化学物质的有前途的溶剂。在这项研究中，开发了一种基于 DES 的微波辅助萃取 (MAE) 方法，用于色谱分析多根螺旋藻中四种生物活性黄酮类化合物。在 Promosil C18 色谱柱上实现色谱分离。在进行 HPLC 分析之前，使用氯化胆碱/乙酰丙酸 (1:2, mol/mol) 作为溶剂通过 DES-MAE 工艺快速提取黄酮类化合物。使用响应面法优化提取参数，与传统的基于溶剂的 MAE 和使用 DES 的超声辅助提取相比，最佳 DES-MAE 快速有效。四种黄酮类化合物的优化 DES-MAE 回收率在 97.80% 到 103.29% 之间。