In this research, novel magnetic nanoparticles based on ultrasonic-assisted magnetic dispersive micro-solid phase extraction and deep eutectic solvent have been developed for the determination of phenolic compounds (naringenin, hesperetin, gallic acid) in fruit juice samples. For this purpose, for the first time, adipic acid-coated magnetic nanoparticles (AD@Fe3O4) as an efficient sorbent were synthesized and identified. In this study, deep eutectic solvents were prepared with available and less-toxic compounds and used as eluent solvent in the desorption step. These solvents are good options instead of conventional organic solvents to reduce hazardous waste products and improve the adsorption capacity. In addition, the extracted analytes were easily isolated from the media by an external magnet, and no special devices were required for phase separation. The screening of some important parameters on the extraction procedure was examined by fractional factorial design. Then, the central composite design was applied to optimize the effective parameters. The optimum conditions for the developed method were obtained as pH: 3.7, the amount of salt: 5% (w/v), the amount of adsorbent: 2 mg, and extraction time: 2 min. Under the optimal conditions, the proposed method demonstrated excellent linearity in the range of 1.0–500.0 μg L 1 for hesperetin and 5.0–500.0 μg L 1 for naringenin and gallic acid (R2 > 0.997). The extraction recoveries were obtained above 91.0%, and the intra-day and inter-day precision (RSD%) lower than 4.8%. Limit of detections (LODs) were in the range of 0.3–2.0 μg L 1. The results indicated that the suggested method is simple, fast, and eco-friendly. At the end, the new method was effectively applied for the determination of phenolic compounds in fruit juice samples.
