A molecularly imprinted polymer monolithic column with dual template and bifunctional monomers for selective extraction and simultaneous determination of eight phenolics from polycarbonate cups.

A molecularly imprinted polymer (MIP) monolithic column was prepared in situ in a pipette tip using phenol and bisphenol A as dual templates, 4-vinyl pyridine and β-cyclodextrin as bifunctional monomers. It was used for the selective and simultaneous solid phase extraction of eight phenolics, including phenol, m-cresol, p-tert-butylphenol, bisphenol A, bisphenol B, bisphenol E, bisphenol Z, and bisphenol AP. The MIP monolithic column was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis and nitrogen adsorption experiment. The results of selective adsorption experiments showed that the MIP monolithic column can selective recognize the phenolics and have excellent adsorption property. The imprinting factor for bisphenol A can be as high as 4.31, and the maximum adsorption capacity for bisphenol Z can reach 201.66 mg g. Under the optimal extraction conditions, a selective and simultaneous extraction and determination method for eight phenolics was established based on the MIP monolithic column and high-performance liquid chromatography with ultraviolet detection. The linear ranges (LRs) of the eight phenolics were 0.5-200 μg L, the limits of quantification (LOQs) and detection (LODs) were 0.5-2.0 μg L and 0.15-0.67 μg L. The method was applied to detect the migration quantity of the eight phenolics from polycarbonate cups and had satisfactory recovery. The method has the advantages of simple synthesis, short extraction time, as well as good repeatability and reproducibility, which provides a sensitive and reliable strategy for extracting and detecting phenolics from food contact material.