Boron nitride-based magnetic nanocomposite for magnetic solid-phase extraction coupled with HPLC-UV for simultaneous determination of three tetracyclines in pork, egg, and milk

Tetracycline antibiotic residue in food is of vital significance for public health. Hexagonal boron nitride (h-BN)-based materials are excellent absorbents for antibiotics, and modification of the h-BN surface would improve its adsorption ability. In this study, a Fe₃O₄-modified h-BN nanocomposite (Fe₃O₄@h-BN) was fabricated by a simple one-step coprecipitation method. The nanocomposite was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, and vibrating sample magnetometer (VSM). Fe₃O₄@h-BN was used as a magnetically recyclable adsorbent for magnetic solid phase extraction (MSPE) of tetracycline (TC), oxytetracycline (OTC), and chlortetracycline (CTC), and the adsorption performance was investigated under different influencing factors, including contact time, adsorbent dosage, pH conditions, and ionic strength. The nanocomposite Fe₃O₄@h-BN was used for the analysis of three tetracyclines (TCs) in pork, egg, and milk samples using MSPE coupled with high-performance liquid chromatography equipped with a UV detector (HPLC-UV). Under the optimized experimental conditions, the recoveries measured for pork, egg, and milk samples ranged from 84.2% to 96.6%, 92.8% to 108.2%, and 84.1% to 102.6%, respectively, with relative standard deviations (RSDs) of 0.3-9.4%, 0.8-9.7%, and 1.3-7.1%, respectively. This work presents a simple and effective method for antibiotic analysis in food samples.