Core-shell magnetic porous organic polymer for magnetic solid-phase extraction of fluoroquinolone antibiotics in honey samples followed by high-performance liquid chromatography with fluorescence detection.

By monomer-mediated in-situ growth synthesis strategy, with hydroquinone and 1,3,5-tris(4-aminophenyl)benzene as monomers, a core-shell magnetic porous organic polymer was synthesized through a simple azo reaction. Based on this, a magnetic solid-phase extraction-high-performance liquid chromatography-fluorescence detection method was proposed for the analysis of fluoroquinolones in a honey sample. With ofloxacin, ciprofloxacin, enrofloxacin, lomefloxacin, and difloxacin as target analytes, factors affecting the extraction efficiency had been optimized. The LODs were 1.5-5.4 ng/L (corresponding to 0.23-0.81 µg/kg in honey). The linear range was 0.005-20 µg/L for difloxacin, 0.01-20 µg/L for ofloxacin, ciprofloxacin and lomefloxacin, and 0.02-20 µg/L for enrofloxacin. The enrichment factor was 84.4-91.7-fold with a high extraction efficiency of 84.4-91.7%. The method was assessed by the analysis of target fluoroquinolones in honey samples, and the recoveries for the spiked samples were 79.3-95.8%. The results indicated that the established magnetic solid-phase extraction-high-performance liquid chromatography-fluorescence detection method is efficient for the analysis of trace fluoroquinolones in honey.