Magnetic dummy molecularly imprinted polymers (MDMIPs) were prepared by combining the surface imprinting technique with computer simulation for selective recognition of phthalate esters (PAEs). A computational study based on the density functional theory was performed to evaluate the template-monomer geometry and interaction energy in the prepolymerization mixture. The MDMIPs were characterized by transmission electron microscopy, scanning electron microscopy, vibrating sample magnetometry, X-ray diffraction, and Fourier transform infrared spectroscopy. They exhibited (a) high saturation magnetization of 53.14 emu g-1 (leading to fast separation), and (b) large adsorption capacity, fast binding kinetics, and high selectivity for PAEs. Subsequently, a molecularly imprinted solid-phase extraction procedure followed by GC-MS was established for selective extraction and determination of 10 PAEs in food samples. Under the optimal experimental conditions, the response (peak area) was linear in the 0.5-100 ng mL-1 concentration range. The limits of detection ranged from 0.15 to 1.64 ng g-1. The method was applied to the determination of PAEs in spiked real samples. The recoveries for 10 PAEs from various foods were in the range of 73.7%-98.1%, with relative standard deviations of 1.7%-10.2%. Graphical abstract Magnetic dummy molecularly imprinted polymers (MDMIPs) were prepared and successfully were applied as a special sorbent for the selective recognition and fast enrichment of 10 PAEs from different complex matrix.
Keywords: Adsorbent; Dummy template; Food analysis; Gas chromatography-tandem mass spectrometry; Magnetic solid-phase extraction; Molecular simulation; Molecularly imprinted polymers; Phthalate esters; Quantum chemical calculations; Surface imprinting.