Rapid Preparation of Magnetic Zinc MOF Molecular Imprinting Polymers and Efficient Pretreatment of Pyrene in Vegetable Oil

A new type of magnetic zinc metal–organic framework molecularly imprinted polymer (MZMMIP) was created by a crystal growth method, combined with molecular imprinting technology. The material was designed to solve the problems associated with metal–organic frameworks, which have the disadvantages of small pore size and low selectivity in the detection field. MZMMIPs were characterized by SEM, XRD, FTIR, TGA, BET, etc. The results showed that MZMMIPs achieved good crystalline form, excellent magnetic separation ability, rich pore structure, and large specific surface area (602.4 m 2 /g). Furthermore, the results of the adsorption experiment show that the crystal growth method with molecular imprint technology not only improved the MZMMIP adsorption capacity (64 mg/g) and microporous aperture, but also accelerated its adsorption (3 min) and elution rate (10 min) on the target product. With the introduction of molecular imprinting technology, MZMMIPs show a suitable adsorption selective performance (selection factor is 1.6) in the adsorption performance test of structural and nonstructural analogs of pyrene. MZMMIPs display good stability and reusability (the adsorption capacity of MZMMIPs decreased by only 21.8% after 10 elution times). The detection method in the study was successfully implemented for the determination of pyrene in vegetable oil, and achieved an excellent detection effect. The detection limit of MZMMIPs to pyrene is 0.11 µg/kg. The recovery ranged from 93.34 to 95.92%.