Fe3O4/ZIFs-based magnetic solid-phase extraction for the effective extraction of two precursors with diverse structures in aflatoxin B1 biosynthetic pathway

The aflatoxin B 1 (AFB 1 ) early warning technique based on precursors is an effective strategy for the prevention of AFB 1 contamination risk. The determination of precursors is imperative to ensure the efficiency of the early warning technique. Herein, a controllable magnetic adsorbent Fe 3 O 4 /ZIFs was first introduced for the effective extraction and determination of averantin (AVN) and sterigmatocystin (ST) precursors in cereal by combining magnetic solid-phase extraction (MSPE) and high-performance liquid chromatography (HPLC). Benefiting from the abundant adsorption sites and multifunctional groups matching the analytes , Fe 3 O 4 /ZIFs effectively and simultaneously extracted AVN and ST with great differences in polarity and structure via multiple interactions. AVN was extracted by Fe 3 O 4 /ZIFs mainly through π–π and hydrophobic interactions, while ST was extracted predominantly by electrostatic interactions and surface complexation. The limits of detection were 0.08 μg kg −1 (AVN) and 0.36 μg kg −1 (ST). The developed method exhibited satisfactory spiked recoveries (79.1%–105.4%) in the determination of AVN and ST in rice. This work provides a novel analytical strategy for further studying AFB 1 early warning technique and the formation and transformation of aflatoxins .