A magnetic molecularly imprinted polymer hierarchical composite adsorbent embedded with a zinc oxide carbon foam nanocomposite for the extraction of sulfonamides

Abstract

A hierarchical composite adsorbent incorporated a nanocomposite of zinc oxide and carbon foam embedded in a magnetic molecularly imprinted polymer (ZnO@CF@Fe3O4-SiO2-NH2@MIP). The adsorbent was used to extract, preconcentrate and determine sulfonamides. The fabricated adsorbent was characterized, the fabrication and extraction conditions were investigated and the extracted sulfonamides were determined using high performance liquid chromatography. The zinc oxide carbon foam nanocomposite helped to improve the adsorption of sulfonamides. The MIP provided highly specific recognition cavities for three sulfonamides and the magnetic material enabled the simple and rapid separation of the adsorbent after adsorption and desorption. Under optimum conditions, the developed strategy provided a good linearity from 2.0 to 150.0 μg L-1 with R2 better than 0.995. The LOD and LOQ were 2.0 and 5.0 μg L-1, respectively. The developed strategy determined sulfonamides in milk and water with extraction recoveries between 84.3 and 96.2% and RSDs lower than 7%. Concentrations of sulfadiazine were found in some milk and water samples at 2.50 and 2.05 μg L-1, respectively. The advantages of the developed nanocomposite adsorbent are high specificity and extraction efficiency, simplicity and convenience, and good stability that enables reuse.