The Synthesis and Characterisation of Retinol-molecularly Imprinted Polymers as a Selective Sorbent in Solid-phase Extraction

The aim of the work is to design and synthesize and evaluate the polymer recognition characteristics of molecularly imprinted polymers selective for trans-retinol (R-MIP). The optimal amount of template and methacrylic acid (MAA) functional monomer as well as ethylene glycol dimethacrylate (EDMA) acts as the crosslinker was examined toward imprinting process using radical polymerization in chloroform solvent. The FT-IR study indicated the interaction between hydroxyl group on trans-retinol and carbonyl group on MAA forms hydrogen bonding. From 1 H-NMR titration, the job’s plot analysis was considered that trans-retinol interacted with MAA in a 1:1 molar ratio of the template-functional monomer complex. The binding isotherm of the imprinted polymer was fitted to the Freundlich model and the binding affinity constant was provided for 0.064 μM. Cross-reactivity study revealed that the binding capability of the imprinted polymer was highest for the template when compared with other structurally related substances (cis-retinol, α, δ, γ-tocopherol, α-tocotrienol and β-carotene). The results proved that the obtained trans-retinol-imprinted polymer is appreciable as specific sorbents for separation of complex mixtures such as crude palm oils.