Synthesis and Evaluation of Ionic Liquid–Mediated Molecularly Imprinted Polymer for Highly Selective Recognition of Dibutyl Phthalate from Liquor Samples

New ionic liquid-mediated molecularly imprinted polymers (ILMIPs) for phthalate esters were developed in this study by the situ thermal polymerization method using methacrylic acid as a functional monomer and dibutyl phthalate (DBP) as a template. The polymer was characterized by scanning electron microscopy and Fourier transform infrared spectrometry. Batch static binding adsorption experiments were carried out to analyze its adsorption performance. The selectivity and adsorption of molecularly imprinted polymers were improved by the ionic liquids 1-butyl-3-methylimidazolium hexafluorophosphate as an excellent auxiliary porogen and solvent. The adsorption process conformed to pseudo–first-order model by kinetics analysis and Sips model by isotherm analysis. Using the prepared ILMIPs as a solid-phase extraction (SPE) sorbent, which indicated that ILMIPs–SPE had a higher enrichment efficiency and a better selectivity for DBP, and the average recoveries of DBP at four spiked levels were in a range of 96.4–101.3% ( n = 5) with relative standard deviation (RSD) ≤6.9%.