Determination of Quinoline Carboxylic Acid Antibiotics in Honey by Ternary Layered Double Hydroxide-Based Magnetic Solid-Phase Extraction Coupled with Liquid Chromatography

Here, Fe₃O₄@FeMgAl-layered double hydroxide (LDH) was synthesized via a coprecipitation method for the magnetic solid-phase extraction (MSPE) of quinoline carboxylic acid antibiotics in five types of honey. Compared with other pretreatment methods, MSPE is simple, time-saving, and cost-effective. Furthermore, compared with traditional adsorbents, Fe₃O₄@FeMgAl-LDH is easy to synthesize and easily dissolves by acid. To harness this characteristic, H₂SO₄ was used to dissolve the Fe₃O₄@FeMgAl-LDH material during the extraction process instead of traditional organic solvent extraction. Thus, the extraction process was efficient and environmentally friendly. By optimizing the factors affecting extraction efficiency, an MSPE-HPLC-UV method was established under optimal conditions for the determination of four quinoline carboxylic acid antibiotics. This method offered the advantages of a wide linear range (0.077–7.000 μg·g^–1), low detection limit (0.023–0.036 μg·g^–1), high coefficient of determination (>0.9988), good precision (4.330–9.318%), and high extraction recovery rate (83.792–104.277%). The study findings show that this method is green and trustworthy for detecting quinoline carboxylic acid antibiotics in honey samples.