Novel magnetic porous biochar derived from degreasing cotton as a multifunctional adsorbent for simultaneous efficient capturing and monitoring of multiple antibiotic residues

The construction of a novel multifunctional adsorbent for simultaneous sensitive detection and capture of multiple antibiotic residues in the environment and food samples remains challenging. In this paper, the novel magnetic porous biochar (MPBC) derived from low-cost degreasing cotton was well-constructed and prepared via a simple solvent-free and one-step carbonization which has a large surface area, 3D porous structure, and good magnetism. The acquired MPBC was first used as multifunctional adsorbents for synchronous sorptive removal, sensitive detection, molecular sieve selection, and magnetic separation, exhibiting excellent adsorption capacity (102.2 mg g−1) for multiple antibiotics (quinolones and sulfonamides) residue. Meanwhile, the MPBC could exclude the relatively large matrix compounds, thus eliminating matrix effects. What's more, this method has a higher detection sensitivity, a lower detection limit (0.043–0.067 μg L−1), and higher enrichment factors (111