Eco-friendly deep eutectic solvents skeleton patterned molecularly imprinted polymers for the separation of sinapic acid from agricultural wastes

A new and facile sinapic acid imprinted polymer coated hydroxyapatite based on deep eutectic solvents (DESs) was prepared and applied as an adsorbent material to selectively extract sinapic acid from squeezed rape seed extract. Different DESs acted as functional monomers and cross-linkers in preparing MIPs. Hydroxyapatite was selected as the core and the imprinting layer was coated evenly on its surface. Batch adsorption tests indicated that the MIPs displayed superior recognition ability by possessing an adsorption capacity of 121 mg g-1. The prepared imprinted materials could be regeneratively and repeatedly used without a significant reduction in adsorption capacity. The abovementioned good performances caused the proposed method to be further applied for the selective extraction of sinapic acid in squeezed rape seed extract. Compared with the previous extraction methods, the facile and eco-friendly method proposed in this work could simultaneously settle the issues “residues of toxic organic solvent” and “lack of specificity and selectivity”. Therefore, the proposed approach would provide a good candidate for the extraction of active ingredients from agricultural wastes.