Determination of benzimidazoles in honey by Fe3O4@SiO2@MPA-TAPT-COF-based magnetic solid-phase and UPLC-MS/MS

This study aimed to synthesize a novel magnetic covalent organic framework (COF)-based material and establish an efficient magnetic solid-phase extraction (MSPE) method for the determination of benzimidazoles (BZDs) in honey. Given the abundant nitrogen atoms in BZDs, the target material (Fe₃O₄@SiO₂@MPA-TAPT-COF) was designed with Fe₃O₄ as the magnetic core and a COF shell polymerized from 5-bromobenzene-1,3-dicarbaldehyde (MPA) and 4,4',4''-(1,3,5-triazine-2,4,6-triyl) trianiline (TAPT). The synthesized Fe₃O₄@SiO₂@MPA-TAPT-COF exhibited considerable specific surface area, good magnetic responsiveness, and excellent reusability. An MSPE method using Fe₃O₄@SiO₂@MPA-TAPT-COF as the adsorbent was developed for the purification of BZDs in honey, followed by quantification via ultra-performance liquid chromatography–tandem mass spectrometry (UPLC-MS/MS). This method featured simple operation, high sensitivity, and good efficiency. Under optimized MSPE conditions, It showed good linearity for 17 BZDs in the concentration range of 0.2–100 μg/L, with correlation coefficients (R²) ≥ 0.9991. The limits of detection (LODs) for BZDs in honey were as low as 0.009–0.342 μg/kg. For spiked honey samples, the recoveries of the 17 target BZDs ranged from 61.44% to 118.90%.These results confirm that Fe₃O₄@SiO₂@MPA-TAPT-COF is a promising adsorbent for sample pretreatment, and the developed method provides a reliable tool for the sensitive and efficient analysis of BZDs in honey. • A novel magnetic Fe₃O₄@SiO₂@MPA-TAPT-COF material was first prepared. • The adsorbent effectively extracts benzimidazoles through multiple interactions. • A new method for the determination of trace benzimidazole insecticides was developed. • The method was successfully applied to benzimidazoles detection in honey.