Construction of hydrophilic magnetic imprinted covalent organic framework composite for targeted separation and enrichment of tetracycline.

Tetracycline (TC) contamination poses a serious environmental and public health threat, therefore this work presents a sensitive and selective TC separation and detection method. Hydrophilic molecularly imprinted polymers (IL-MMIPs) were designed for the first time, using magnetic graphene oxide modified covalent organic framework (MGO-COF) as the support, double ionic liquids N-trimethyl-(4-vinylbenzyl) ammonium chloride and 1-vinyl-3-ethylimidazole bromide as functional monomer and cross-linker, respectively. The IL-MMIPs exhibited high adsorption capacity and fast adsorption kinetics for TC through the recognition of surface molecular imprinting and the strong electrostatic interaction and hydrogen bonding between ionic liquids. And the IL-MMIPs showed outstanding water-compatibility thanks to the incorporation of double ionic liquids. Under the optimal conditions, the detection limit of MSPE-IL-MMIPs-HPLC-UV was 0.20 μg/L, and the correlation coefficient R2 was 0.9999. The TC was extracted from medical wastewater by IL-MMIPs with a recovery rate of 93.0-105.3 %. Therefore, the established method based on IL-MMIPs has high sensitivity and can be used as a new strategy for the detection of tetracycline antibiotics in water systems.