Flavonoids are a group of polyphenolic antioxidants that play an important role in the human diet [1]. Flavonoids have biological properties such as antioxidants, anti-carcinogenic, and anti-inflammatory [2]. The preconcentration and clean-up steps are necessary for the determination of analytes in food samples. Deep eutectic solvents (DESs) are new eco-friendly solvents. A DES (Tetramethylammonium chloride: ethylene glycol) is composed of parts, including the hydrogen bond acceptor and the hydrogen bond donor [3]. Tetramethylammonium chloride is available, and nontoxic salt. The aim of this study was to investigate the application of the DESs as acceptor phase in solvent bar microextraction for determine flavonoid of apple sample.
