Preparation of magnetic mixed-templates molecularly imprinted polymer for the separation of tetracycline antibiotics from egg and honey samples

Novel magnetic molecularly imprinted polymers were prepared using bilayer modified Fe3O4 magnetite as the magnetically susceptible component, oxytetracycline and chlortetracycline as the mixed-template molecules, and methacrylic acid as the functional monomer. The magnetic polymers were applied to the separation of tetracycline antibiotics from egg and honey samples. The sample, polymers and extraction solvent were blended and stirred together. The extraction and clean-up procedures were carried out in a single step. The analytes could be extracted from the sample matrix to the polymers directly or through the extraction solvent as the medium. When the extraction was complete, the polymers which had adsorbed the analytes were easily separated from the sample matrix by an adscititious magnet. The analytes eluted from the polymers were determined by high liquid chromatography spectrometry. The recoveries obtained to be 76.2% to 95.8% with relative standard deviations in the range of 3.1-13.2%. The limit of detection was less than 0.2 ng g(-1). The feasibility of this method was proven by analysis of incurred egg and honey samples. Compared with the classical method which uses more steps including solvent extraction, centrifugation, clean-up and concentration by solid-phase extraction, the proposed method decreased the complexity and improved the reliability.