Extraction and determination of flavonoids in fruit juices and vegetables using Fe 3 O 4 /SiO 2 magnetic nanoparticles modified with mixed hemi/ad-micelle cetyltrimethylammonium bromide and high performance liquid chromatography

Extraction and determination of three flavonoids (morin, quercetin, and kaempferol) were performed by dispersive magnetic solid phase extraction based on mixed hemi/ad-micelles and high-performance liquid chromatography with UV detection. The Fe O /SiO nanoparticles were synthesized and characterized by X-ray diffraction, FTIR, scanning electron microscopy, and thermogravimetric analysis. Fe O /SiO nanoparticles coated with mixed hemi/ad-micelles cetyltrimethyl ammonium bromide was applied as a sorbent and used for extraction of flavonoids. Effective parameters on the extraction recovery such as amount of magnetic nano particles, volume of cetyltrimethyl ammonium bromide solution with specific concentration, pH of sample solution, adsorption equilibrium time, volume of desorption solvent, and desorption times were evaluated and optimized using fractional factorial design and central composite design. Under the optimum condition limit of detection and linearity were 0.83, 2.7-500.0 for morin, 0.18, 0.7-500.0 for quercetin and, 0.37, 1.3-500.0 µg/L for kaempferol. The extraction recovery with relative standard deviation were 97.88, 1.94 for morin, 95.77, 0.80 for quercetin, and 93.35, 1.45 for kaempferol. The proposed method was applied for simultaneous extraction and determination of flavonoids in several fruit juices and vegetable samples.