Surface-Imprinted Magnetic Carboxylated Cellulose Nanocrystals for the Highly Selective Extraction of Six...

We herein describe a novel adsorbent based on molecularly imprinted polymers (MIPs) on the surface of magnetic carboxylated cellulose nanocrystals (Fe₃O₄@CCNs@MIPs) for the separation and purification of six fluoroquinolones (FQs) from egg samples. The obtained Fe₃O₄@CCNs@MIPs not only exhibited a large surface area and specific recognition toward FQs, but also were easily gathered and separated from the egg samples using an external magnetic field. The morphologies and surface groups of the Fe₃O₄@CCNs@MIPs were assessed by X-ray photoelectron spectroscopy, transmission electron microscopy, vibrating sample magnetometry, X-ray diffraction, thermogravimetric analysis, Fourier transform infrared spectroscopy, and Brunauer-Emmett-Teller surface area analysis. The Fe₃O₄@CCNs@MIPs exhibited high selectivity toward six structurally similar FQs. An enrichment approach was established for the measurement of six FQs from egg samples using Fe₃O₄@CCNs@MIPs coupled to high-performance liquid chromatography. The recovery of spiked FQs ranged from 75.2-104.9% and limit of detection was in the range of 3.6-18.4 ng g^-1 for the six FQs. Therefore, the proposed method is a promising technique for the enrichment, separation, and determination of FQs from biomatrices.