Determination of Five Fluoroquinolones in Aquatic Products by High Performance Liquid Chromatography with Solid Phase Extraction Using Metal-Organic Framework as Sorbent

A novel metal-organic framework (MOF) material, UiO-66-NH₂, was synthesized using a solvothermal method. Subsequently, a high performance liquid chromatography (HPLC) method with solid phase extraction using UiO-66-NH₂ was established for the simultaneous detection of five fluoroquinolone (FQ) residues in aquatic products. The sample was extracted with acetonitrile in 1.0% formic acid, degreased with n-hexane, and concentrated by rotary evaporation. The extract was then redissolved in aqueous ammonia solution at pH 8.0. The FQs were enriched and purified with a solid phase extraction (SPE) column filled with 30 mg of UiO-66-NH₂ using 6 mL of 20% acetic acid-methanol solution as the eluent. The collected eluate was blown to dryness under nitrogen, redissolved and detected by HPLC with a fluorescence detector. Under the established experimental conditions, good linear relationships were achieved for the five FQs in the concentration range of 0.005–0.50 mg/L, with determination coefficients (R²) of 0.9999–1.0. The recovery rates ranged from 81.4% to 104.8% with relative standard deviation (RSD) of 1.29%–4.93%, and the limits of detection (LOD) were in the range of 0.21–2.05 μg/kg. The prepared SPE column could be reused up to five times, which was environmentally friendly and costeffective. The established method had good accuracy, precision, reproducibility, and selectivity, and was suitable for the simultaneous detection of various trace FQ residues in aquatic products.