pH-switchable vortex-assisted liquid-liquid microextraction using hydrophobic eutectic solvents for the extraction of phthalate esters from water, fruit juice, and milk samples.

Phthalate esters (PAEs) are widely used in the plastic industry, but their accumulation in living organisms raises concerns, necessitating ongoing monitoring. This study explores the application of switchable hydrophobic eutectic solvents (HESs) for the sustainable extraction of PAEs. Among different HESs tested, an equimolar thymol: octanoic acid mixture demonstrated the highest potential in extracting PAEs from water, fruit juice, and milk samples, achieving recoveries of 91 % to 108 %. Calibration was linear over the concentration range of 1-300 μg/L, with detection limits of 0.3-1.0 μg/L under the extraction conditions optimized using Box-Behnken design. The method provided enrichment factors in the range of 138-152. We also evaluated the interactions between the selected HES and the target PAEs using quantum chemistry. The environmental impact of the proposed method was evaluated using the GREENness metric tools, including AGREE and AGREEprep. The results revealed that this microextraction method can be a sustainable alternative for determining PAEs.