Amino-functionalized covalent organic framework for the effective capture of neonicotinoids from honey, beverages and water

An amino-functionalized covalent organic framework was synthesized. • NH 2 -PyCOF exhibited enhanced hydrophilicity and multiple interaction sites. • NH 2 -PyCOF exhibited superior adsorption ability to neonicotinoid insecticides (NTIs). • A SPE-HPLC-MS method was built to detect NTIs in honey, beverage, and water. An amino-functionalized pyrazine-based highly conjugated covalent organic framework (NH 2 -PyCOF) was synthesized via a post-synthetic modification strategy and applied as an adsorbent for the solid-phase extraction (SPE) of four neonicotinoid insecticides (NTIs) in honey, beverage and water samples. NH 2 -PyCOF combines a highly conjugated pyrazine skeleton with multiple amino sites, which not only enhances its hydrophilicity but also provides multiple interaction sites, including hydrogen-bonding and π-π stacking sites. When NH 2 -PyCOF-based SPE was coupled with HPLC-MS, the method demonstrated low detection limits (0.025–0.10 ng mL -1 for peach beverage samples, 0.01–0.03 ng mL -1 for water samples and 0.20–0.80 ng g -1 for honey samples) and satisfactory recoveries (86.0%-111%) with relative standard deviations below 8.4%. The NH 2 -PyCOF-SPE-HPLC-MS method exhibits exceptional sensitivity and reproducibility, providing a reliable and efficient approach for monitoring trace NTI residues in complex matrices. Download: Download high-res image (322KB) Download: Download full-size image