Development of molecularly imprinted polymers via dual polymerisation strategies for targeted isolation of Ethyl p-Methoxycinnamate from Kaempferia galanga L. extract

• MIP developed for selective isolation of EPMC from kaempferia galanga. • Bulk and suspension polymerization were compared for MIP preparation. • Bulk MI-SPE outperformed suspension due to initiator incompatibility. • MI-SPE B2 improved recovery and purity of EPMC isolation. • The approach reduces cost and simplifies workflow compared with conventional methods. The rhizome of Kaempferia galanga L. contained ethyl p-methoxycinnamate (EPMC) as a major component of its essential oil. Despite the abundance of EPMC in the plant, conventional isolation methods yielded only 0.5 – 2.5 %. This study developed molecularly imprinted polymers (MIPs) via bulk and suspension polymerisation to enhance the selective isolation of EPMC from K. galanga extracts. Six functional monomers were screened for their binding affinity with EPMC. 2-hydroxyethyl methacrylate (HEMA) in chloroform and methacrylic acid (MAA) in n -hexane were selected for further investigation. Stoichiometric analysis established optimal template-to-monomer ratios of 1:6 for HEMA and 1:7 for MAA. Eight MIP formulations and their corresponding non-imprinted polymers (NIPs), were synthesised using these monomers via both polymerisation methods. Characterisation using Fourie Transform Infra-Red (FTIR), Scanning Electron Microscope (SEM), Brunauer-Emmett-Teller (BET), and Particle Size Analysis (PSA) revealed that bulk polymers exhibited larger, irregular, and non-uniform particles compared to those produced by suspension polymerisation. Adsorption studies confirmed that the MIPs follow Freundlich isotherms, with MIP B2 (bulk, MAA, 1:7 ratio) exhibiting the highest binding affinity (KF = 0.081 mg/g). MIP B2 also demonstrated superior performance in the solid-phase extraction of EPMC from extracts, achieving recoveries of up to 82.4 % ± 5.52 and imprinting factors above 1.3. Selectivity tests confirmed strong discrimination of EPMC over structural analogues. In conclusion, MIP B2 offers a selective, efficient, and scalable method for EPMC isolation. These findings supported the continued development of tailored MIPs for natural product purification and provided a foundation for future optimisation of monomer-initiator systems and polymerisation parameters.