Effective extraction of aflatoxin B1 and its three precursors by ionic liquid-impregnated covalent triazine polymer for accurately tracking their dynamic changes

Early warning detection based on aflatoxin B 1 (AFB 1 ) biosynthesis precursors is an effective strategy for the prevention of AFB 1 contamination. However, the development of effective methods for accurately tracking the dynamic changes of AFB 1 and its precursors presents a major challenge. This difficulty is due to the continual variations in precursor species and concentrations, structural differences of AFB 1 and its precursors, as well as the complexity of the dynamically changed sample matrix. Herein, an ionic liquid-impregnated covalent triazine polymer composite (IL@CTP) was fabricated, which exhibited excellent extraction performance for structurally different AFB 1 and its three typical precursors in moldy grains. The high performance was attributed to the multiple interactions between the prepared composite and analytes, as well as a mesopore filling effect. The combined use of IL@CTP with dispersive solid-phase extraction and ultra high-performance liquid chromatography-mass spectrometry achieved negligible matrix effects, with low limits of detection (0.01–0.03 ng/g), wide linearity (0.06–200 ng/g) and satisfactory relative recoveries of 85.3 %-113.0 %. Therefore, the developed method can accurately track the dynamic changes of AFB 1 and its precursors in stored maize inoculated with Aspergillus flavus . Correlation analysis between AFB 1 and its precursors showed that it was necessary to simultaneously serve averantin, O-methylsterigmatocystin and sterigmatocystin as early warning molecules, allowing the accurate identification of AFB 1 contamination risks up to 5 days in advance.