Synthesis and characterization of molecularly imprinted polymers with modified rosin as a cross-linker and selective SPE-HPLC detection of basic orange II in foods

Abstract

Basic orange II (BOII) is an alkaline azo dye that is listed as a prohibited substance in food additives. In order to develop a novel molecularly imprinted polymer (MIP) with modified rosin as a cross-linker for the selective solid-phase extraction (SPE) of BOII in foods, MIP was synthesized using BOII as the template molecule, acrylamide as the functional monomer, and maleic rosin glycol acrylate (MRGA) as the cross-linking agent. MIP was characterized using scanning electron microscopy, Fourier transform infrared spectroscopy and thermogravimetric analysis. Compared to the imprinted polymers prepared by the traditional cross-linker, MIP showed a highly imprinting capacity, significant selectivity, hardness and toughness, and it could be used as a SPE material, as well as for the detection of illegal addition of BOII in food. In the sample with a spiked level of 5–11 mg kg⁻¹, BOII in foods revealed an average recovery rate of 68.43–80.25% with a precision (relative standard deviation) of less than 1.2%.