Effective synthesis of magnetic porous molecularly imprinted polymers for efficient and selective extraction of cinnamic acid from apple juices

- Novel MPMIPs using mSiO2 as sacrifice support was fabricated.
- Economic imprinting more MIPs into mesopores for high adsorption.
- Porous structure for fast binding kinetics.
- MPMIPs for the rapid, selective and effective extraction of CMA.
- MPMIPs exhibited good application potential in complex matrices.

An effective strategy was proposed to prepare novel magnetic porous molecularly imprinted polymers (MPMIPs) for highly selective extraction of cinnamic acid (CMA) from complex matrices. Characterization and various parameters affecting adsorption and desorption behaviors were investigated. Results revealed adsorption behavior between CMA and MPMIPs followed Freundlich equation adsorption isotherm with a maximum adsorption capacity at 4.35 mg/g and pseudo-second-order reaction kinetics with equilibrium time at 60 min. Subsequently, MPMIPs were successfully used to selectively extract CMA from apple juice with a relatively satisfactory recovery (92.7-101.4%). Coupling with high-performance liquid chromatography and ultraviolet detection (HPLC-UV), the limit of detection (LOD) for CMA was 0.006 µg/mL, and the linear range (0.02-10 μg/mL) was wide with correlation coefficient at 0.9995. Finally, the contents of CMA in two kinds of apple juices were determined as 0.132 and 0.120 μg/mL. Results indicated the superiority of MPMIPs in the selective extraction field.

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