Abstract
The stir bar was prepared by coating biochar on a magnetic core using cellulose aerogel (CA) as support and adhesive. The stir bar is ideal for stir-bar sorptive extraction (SBSE), since macroporous CA network provides accessible transport channels for analytes. Besides, raw materials of biochar and CA are natural, and the preparation process is organic solvent-free. The stir bar was applied to extract bisphenols in canned foods. Extraction parameters were studied, and our lab-made stir bars outperformed commercial ones in extraction speed and capacity. Coupled to UPLC-MS/MS, the established approach supported food safety surveillance. To our knowledge, this is the first application of biochar/CA in SBSE, introducing a green coating binder for SBSE. This rapid (extraction time: 8 min), sensitive (LOD: 1.0-3.5 ng/L and 11-44 ng/kg for liquid and solid foods), and reduced-solvent (volume of organic solvent in SBSE: 1 mL) SBSE method offers an innovative alternative for sample preparation.