Rapid and Sensitive Determination of Fluoroquinolones in Tilapia Using a Cost-Effective UPLC-MS/MS Method Based on Dummy Molecularly Imprinted Polymers

This study developed a novel dummy molecularly imprinted polymer (DMIP) via emulsion polymerization for rapid, sensitive, and simultaneous detection of four fluoroquinolone (FQ) antibiotic residues in tilapia. The DMIP, coupled with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), was thoroughly characterized for its structure and adsorption properties. Optimized parameters revealed a rough surface morphology with aggregated spherical structures (400-500 nm). Compared to a non-imprinted polymer (NIP), the DMIP exhibited faster adsorption kinetics and enhanced selectivity towards enrofloxacin and related FQ compounds. The DMIP-UPLC-MS/MS method achieved satisfactory recoveries (77-105%) for the four target FQs in tilapia, with intra-day and inter-day relative standard deviations of 3.6-9.2% and 4.0-11.7%, respectively. Method detection limits (LODs) ranged from 0.02-0.06 µg/kg, while quantification limits (LOQs) ranged from 0.06-0.2 µg/kg. This novel method demonstrates excellent potential for highly sensitive and selective monitoring of trace FQ residues in aquatic food products.