Rational selection of 4,4',4″-(1,3,5-triazine-2,4,6-triyl) trianiline-based covalent organic framework as adsorbent for effective co-extraction of aflatoxins, zearalenone and its metabolites from food and biological samples.

Aflatoxins, zearalenone and its metabolites, as representative hazard mycotoxins cause adverse effects on food safety and human health. Developing a sensitive and reliable extraction and detection method is of great importance for monitoring their residue and exposure levels. In contrast to traditional trial-and-error selection steps, 4,4',4″-(1,3,5-triazine-2,4,6-triyl) trianiline covalent-bonding with 2,5-dihydroxyterephthalaldehyde, namely TAPT-OH-COF was screened as a potential adsorbent utilizing density functional theory calculations prior to the synthesis procedure. After experimental verification, magnetic TAPT-OH-COFs were prepared, characterized and applied for the extraction of aflatoxins, zearalenone and its metabolites from food and biological samples, coupled with high-performance liquid chromatography tandem mass spectrophy detection. Under the optimal conditions, the developed method exhibited low limits of quantification (0.05-0.50 μg/kg), satisfactory recoveries (75.8 %-110.9 %) and good precision with intraday and interday relative standard deviations (RSDs) not exceeding 12.2 %. This study may provide great potential for the selection of candidate adsorbents for multi-mycotoxins extraction from complex samples.