Three-template magnetic molecular imprinted polymer for the rapid separation and specific recognition of illegal cooking oil markers

A novel multifunctional three-template magnetic molecularly imprinted polymer (MMIP) is designed for the simultaneous determination of illegal cooking oil (ICO) markers, including capsaicin, dihydrocapsaicin and eugenol. The binding experiments of the above three chemicals on the MMIP demonstrated high specificity, excellent selectivity, reusability and rapid separation. Particularly, the prepared MMIP coupled with high-performance liquid chromatography equipped with a fluorescence detector (HPLC-FLD) successfully applied for the identification of ICO, and the detection process does not need the tedious processes of liquid phase extraction, centrifugation or filtration, concentration, etc. Moreover, the limits of detection (LODs) and limits of quantification (LOQs) obtained for the three compounds are 0.05685–0.1388 μg/kg and 0.1895–0.4625 μg/kg, respectively. Quantitative recoveries are 87.9%–104.1% and 89.3%–102.4% for two kinds of edible oil at spiking levels of 1.0, 10.0, and 50.0 μg/kg.