Preparation of magnetic molecularly imprinted polymer for the separation of tetracycline antibiotics from egg and tissue samples

Magnetic molecularly imprinted polymers were prepared using hydrophobic Fe₃O₄ magnetite as the magnetically susceptible component, oxytetracycline as template molecule, methacrylic acid as functional monomer, and styrene and divinylbenzene as polymeric matrix components. The polymers were applied to the separation of tetracycline antibiotics from egg and tissue samples. The extraction and clean-up procedures were carried out in a single step by blending and stirring the sample, extraction solvent and polymers. The analytes can be transferred from the sample matrix to the polymers directly or through the extraction solvent as medium. When the extraction was complete, the polymers adsorbing the analytes were easily separated from the sample matrix by an adscititious magnet. The analytes eluted from the polymers were determined by liquid chromatography–tandem mass spectrometry. The recoveries ranging from 72.8% to 96.5% were obtained with relative standard deviations in the range of 2.9–12.3%. The limit of detection was less than 0.2 ng g⁻¹. The feasibility of this method was validated by analysis of incurred egg and tissue samples, and the results were compared with those obtained by the classical method in which solvent extraction, centrifugation, and subsequent clean-up and concentration by solid-phase extraction were applied. The proposed method reduced the complicacy of classical method and improved the reliability of method.