Determination of Benzimidazoles in Milk and Pork by Magnetic Graphene Oxide‐Covalent Organic Framework Composite‐Based Magnetic Solid‐Phase Extraction Combined With High‐Performance Liquid Chromatography–Tandem Mass Spectrometry

ABSTRACT

Benzimidazoles are a crucial class of anthelmintics, which are widely applied to manage parasitic infections in food‐producing animals. Due to their potential toxicological effects on humans, the determination of benzimidazole residues in animal‐derived foods is essential for safeguarding public health. In this work, a magnetic graphene oxide‐covalent organic framework composite was synthesized via a facile room‐temperature Schiff base reaction and used as a sorbent for magnetic solid‐phase extraction. Subsequently, a magnetic solid‐phase extraction method coupled with liquid chromatography–tandem mass spectrometry was developed for the determination of 17 benzimidazoles. The extraction conditions were investigated in detail. Under the optimal conditions, the limits of detection for the 17 benzimidazoles ranged from 0.1 to 2 ng L ⁻¹ in the extract, corresponding to 0.2–4 ng L ⁻¹ in milk and 0.4–8 ng L ⁻¹ in pork, and the enrichment factors ranged from 63.3 to 74.6. The developed method was applied to determine the 17 benzimidazoles in milk and pork powder samples. In the pork powder sample, albendazole, albendazole sulfoxide, albendazole sulfone, and albendazole‐2‐aminosulfone were detected at 0.190, 0.340, 0.530, and 0.116 mg kg ⁻¹ , respectively.