Molecularly imprinted polymer-based HPLC column and smart syringe for selective extraction of quercetin from complex...

Quercetin (QR) is a bioactive flavonoid naturally present in various fruits and vegetables, known for its potent antioxidant, antidiabetic, and anti-inflammatory activities. Efficient and sustainable extraction of QR is essential for its wide-ranging applications as a nutraceutical; however, conventional extraction techniques are often time-consuming, solvent-intensive, and environmentally unfriendly. In this study, a quercetin-imprinted polymer (QR-MIP) was synthesized via bulk polymerization using 2-hydroxyethyl methacrylate (HEMA) as the functional monomer and ethylene glycol dimethacrylate (EGDMA) as the crosslinker. The resulting polymer was characterized by SEM, FT-IR, BET, and TGA to confirm its morphological, structural, and thermal properties. Batch rebinding experiments revealed that the QR-MIP exhibited a high binding capacity of 26.7 mg/g, markedly exceeding that of the non-imprinted polymer (6.9 mg/g), with an imprinting factor of 3.8. The adsorption behavior was well-described by the Langmuir isotherm and pseudo-second-order kinetic model, indicating homogeneous and specific binding interactions. Selectivity assessments demonstrated the superior molecular recognition of QR-MIP toward quercetin compared to structurally similar analogs, confirming the presence of specific imprinting sites. The developed MIP was successfully integrated into an HPLC column and a smart syringe system for selective extraction and preconcentration of quercetin from complex matrices utilizing a low volume of less toxic tetrahydrofuran The proposed approach enables sustainable multi-cycle purification while consuming only a few milliliters of organic solvent, in contrast to the liters typically required in conventional protocols. This work presents a novel, green, and cost-effective approach for targeted enrichment of quercetin, offering promising potential for the selective isolation of other nutraceuticals and natural bioactive compounds.