Synthesis and application of magnetic surface molecularly imprinted polymers in selective solid-phase extraction of epoxy triglyceride from deep frying oil

As the major oxidized triglycerides (ox-TGs), epoxy triglyceride is one of the toxic polar components from deep frying oil. However, the conventional methods are difficult to separate epoxy triglyceride from other ox-TGs due to their similar molecular and structures. To address the problem, a novel magnetic solid-phase extraction approach based on a surface molecularly imprinted polymers was developed. The polymers coated on Fe3O4 nanoparticles (Fe3O4@MIPs) were synthesized and used as highly selective sorbents for capture epoxy triglyceride from deep frying oil. They have high adsorption capacity (58.3 mg/g), stable equilibrium adsorption time (60 min) and excellent specificity. This method had a satisfactory linear relationship in the range of 0.2-10 mg/L (R-2 = 0.997), and the detection limit of epoxy triglyceride was 0.0599 mg/L. Results indicated that Fe3O4@MIPs could not only specifically separate epoxy triglycerides, but also provided a potent idea for the separation of other ox-TGs from deep frying oil.