A rapidly synthesized magnetic microporous organic network for ultrasensitive detection of non-steroidal anti-inflammatory drugs in fish.

Non-steroidal anti-inflammatory drugs (NSAIDs) residues pose a potential threat to aquatic ecosystems and food safety. In this work, novel imine bond/pyridine nitrogen-rich magnetic microporous organic networks (MMONs-Br and MMONs-I) were synthesized via a facile one-pot strategy using brominated and iodinated precursors for the detection of NSAIDs in fish. Brunauer-Emmett-Teller analysis revealed a striking 11-fold difference in specific surface areas between the two materials (MMONs-Br: 293.99 m/g; MMONs-I: 26.87 m/g), with pore size distribution analysis revealing that the steric hindrance of the iodinated precursor constrained the structure of MMONs-I. MMONs-Br exhibited superior performance due to its tailored microporosity, excellent magnetic responsiveness (12.30 emu/g), and abundant adsorption sites (pyridine moieties, amino groups), enabling efficient NSAIDs extraction. A MMONs-Br-based magnetic solid-phase extraction method coupled with HPLC-UV was developed, showing good linearity (0.150-500 μg/L), low detection limits (0.054-0.151 μg/L), and satisfactory quantification limits (0.150-0.500 μg/L) that are superior to those of traditional materials. The recoveries in fish samples were 85.5-99.9 %. This study not only provides a new method for the detection of NSAIDs in fish, but also demonstrates a viable strategy for synthesizing high-performance magnetic microporous organic networks tailored for food safety and aquatic environmental pollutant monitoring applications.