Rapid Enrichment and Sensitive Detection of Trace Chloronicotinyl Insecticide Residues in Honey Samples Based on Magnetic Covalent Organic Framework

Establishing an effective method for insecticide residue analysis is critical for food safety control. This study reported a convenient and sensitive approach for extracting and analyzing trace chloronicotinyl insecticides (CNIs) in honey samples. A magnetic covalent organic framework (Fe₃O₄@PyTTA-DHPA-COFs) was synthesized and employed as an adsorbent in magnetic solid phase extraction (m-SPE). The Fe₃O₄@PyTTA-DHPA-COFs exhibited efficient and rapid adsorption (5 min) for CNIs. The m-SPE-HPLC-MS/MS method for trace analysis of CNIs in honey samples was established with good linearity (0.5-200 ng g^-1) and a low limit of quantitation (0.05-0.95 ng g^-1). CNI residues (0.93-4.38 ng g^-1) were detected in real honey samples, much lower than the maximum residue levels (MRLs) of CNIs in honey. The recoveries of CNIs in spiked honey samples were 72.1-106% with RSD < 9.5%. The successful application demonstrates the potential of this method in trace analysis of CNIs residues.