Highly graphitized carbon with enhanced π–π interactions as efficient solid phase extraction adsorbent for ultra-sensitive analysis of aflatoxin B1 in vegetable oils

Aflatoxin B1 (AFB1) threatens food safety due to its persistence in oils. Carbon-based solid-phase extraction (SPE) methods are effective for detecting AFB1 in aqueous food matrices, but employing it in oils is challenging due to non-polar environments. We developed highly graphitized carbon materials (HGC) with enhanced π-π interactions for AFB1 extraction in oil through a transition metal (Fe, Co, Ni)-assisted carbonization process. Adsorption experiments revealed that FeO/Fe 3 O 4 /HGC exhibited a superior AFB1 adsorption capacity of 1179.99 μg g −1 , outperforming Ni/Co-HGC and pure carbon by 4–6 times. Density functional theory revealed the electron-deficient graphitized carbon structures supported by magnetic FeO/Fe 3 O 4 clusters enhance π-π interactions with AFB1, with pore filling and hydrophobicity further aiding adsorption. Combining FeO/Fe 3 O 4 /HGC-SPE with HPLC-FLD achieved ultra-sensitive AFB1 detection in vegetable oils (2.0 pg g −1 limit). This study provides an effective method for AFB1 detection in vegetable oils, supporting the monitoring and control of contamination to enhance food safety.