New natural deep eutectic solvent for vortex-assisted liquid–liquid microextraction for the determination of bisphenols in beverages

A novel hydrophobic natural deep eutectic solvent (NADES) was designed and prepared to selectively enrich biphenolic compounds. The NADES was prepared by blending different molar ratios of octanol and menthol. Various important parameters that influence the extraction efficiency were optimized, including the composition of NADES components, volume, the influence of salt, extraction time, and pH. The experimental results demonstrated that the method exhibited a wide linear range (5–1000 μg/L) with a linear correlation coefficient (R2) exceeding 0.995. The limits of detection (LOD) and quantification (LOQ) ranged from 0.44 to 0.96 μg L−1 and 1.33 to 3.16 μg L−1, respectively. Furthermore, quantum chemical calculations were utilized to analyze the electrostatic potentials of menthol, octanol, water, and the three biphenolic compounds, providing insights into the extraction mechanism of NADESs. The environmental impact of the proposed method was assessed using the ComplexGAPI and Whiteness method, revealing its eco-friendliness. Finally, the method was successfully employed for the extraction and determination of the three bisphenols in beverage samples.