Facile synthesis of magnetic hyper-crosslinked porous polymer for efficient extraction and sensitive determination of nitroimidazole antibiotics

Antibiotics are a class of emerging organic pollutants that pose serious risk to human health and the environment. Nitroimidazoles (NDZs), as a group of important antibiotics, are widely used in livestock and poultry. However, their toxicity has caused world-wide public attention. Based on the idea of turning trash into treasure, in this study, a novel magnetic hyper-crosslinked polymer (M-HCP) was facilely synthesized via Friedel-Crafts reaction by crosslinking wasted polystyrene foam with 1,4-bis(chloromethyl)benzene in the presence of Fe3O4. The prepared M-HCP was characterized by scanning electron microscopy, transmission electron microscopy, Fourier-transform infrared spectroscopy, Brunauer-Emmett-Teller surface area and porosity measurements. The M-HCP showed a high adsorption ability for NDZs including ronidazole, secnidazole, dimetridazole and ornidazole. By coupling M-HCP based magnetic solid-phase extraction with high performance liquid-phase chromatography-ultraviolet detector, a sensitive method was developed for the determination of four NDZs environmental water. Under optimal conditions, a good linearity was obtained in the range of 0.04-100 ng center dot mL- 1 with the correlation coefficients above 0.9993. Low limits of detection were achieved between 0.01 and 0.03 ng center dot mL-1. The developed method was successfully applied to simultaneously determine four NDZs in environmental water, with recoveries from 94.0 % to 105 % and relative standard deviations below 4.8 %, demonstrating that the method has a good sensitivity and accuracy for the determination of NDZs in environmental water. This work not only provides a good alternative for effective detection of trace NDZs, but also has great significance in environment protection and sustainable development by conversing wastes into higher-valueadded materials.