Self-assembled Fe₃O₄-COOH @ hydrogen-bonded organic framework composites for magnetic solid-phase extraction of...

Magnetic solid-phase extraction (MSPE) technology for tetracycline (TCC) was developed by employing the novel and pre-designed Fe₃O₄-COOH@hydrogen-bonded organic frameworks (HOFs) adsorbents in complex food samples. The HOF shell was grown onto the Fe₃O₄-COOH core by in-situ self-assembled method. The excellent MSPE performances with less solvent, less adsorbent and time consumption were derived from the hydrogen bonding, π-π and hydrophobic interactions between HOF shell and TCC. Combined with HPLC analysis, Fe₃O₄@ HOFs adsorbent reduced matrix effects and the established MSPE-HPLC method for TCC gave the linearity of 0.001-6 μg mL^-1 with the limit of detection 0.0003 μg mL^-1. The recoveries in pure milk, canned yellow peach and carrot were 82.4-103.7 %. The method provided a simple, efficient and dependable alternative to monitor trace TCC antibiotics in food or environmental samples.