Synthesis and Characterization of Hydrophobic Natural Deep Eutectic Solvent‐based Molecularly Imprinted Polymers for Selective Extraction of Aflatoxins and Determination With Liquid Chromatography‐Tandem Mass Spectrometry

Abstract

ABSTRACT A green approach to molecularly imprinted polymer synthesis is presented through the use of natural deep eutectic solvents. The polymer prepared for the selective adsorption of aflatoxins was synthesized via precipitation polymerization using 5,7‐dimethoxycoumarin as a template and a thymol/methacrylic acid deep eutectic solvent as both porogen and functional monomer. Fourier‐transform infrared spectroscopy and proton nuclear magnetic resonance were used to confirm the formation of hydrogen bonds between thymol and methacrylic acid during solvent formation. The prepared polymer had higher selectivity for aflatoxins than co‐occurring competing mycotoxins. The effect of pH, initial concentration, contact time, and temperature was examined and optimized through batch adsorption studies. High adsorption capacity (9.44–9.71 mg/g) was observed at pH 7, using 5 mg/L initial aflatoxin concentration, and after 60 min contact time. The adsorption isotherm and kinetic studies demonstrated good agreement with the Langmuir isotherm and pseudo‐second‐order kinetic model, respectively. Further, the synthesized polymers were characterized and evaluated for selectivity, reusability, and greenness, indicating their promise as environmentally friendly materials for future application in aflatoxin determination from food matrices. To the best of our knowledge, this is the first report on the use of a natural deep eutectic solvent‐based molecularly imprinted polymer for aflatoxins using a dummy template.