Zeolitic imidazolate framework functionalized magnetic multiwalled carbon nanotubes as efficient adsorbents for rapid extraction of fluoroquinolones

Herein, a new, environmentally friendly, and economical magnetic solid-phase extraction method for fluoroquinolones (FQs) from milk samples was developed using novel recyclable zeolitic imidazolate framework functionalized magnetic multiwalled carbon nanotubes (Fe 3 O 4 @MWCNTs@SiO 2 @ZIF-8) as adsorbents. Various characterization techniques, including scanning electron microscopy, N 2 adsorption-desorption analysis, and vibrating sample magnetometry, demonstrated that the adsorbent possessed a remarkable specific surface area, pore volume, and superparamagnetic properties, rendering it an excellent adsorbent. Combined with high-performance liquid chromatography, this method exhibited excellent linearity (R 2  ≥ 0.9991) over the concentration range of 0.5–500 μg L −1 , low limits of detection (0.10–0.34 μg kg −1 ), and low limits of quantification (0.30–1.00 μg kg −1 ). Finally, the developed method was successfully applied to analyze FQs in milk samples with recoveries ranging from 83.3% to 107.7% and relative standard deviations below 4.2%. The high efficiency and sensitivity of this method highlight the potential application of Fe 3 O 4 @MWCNTs@SiO 2 @ZIF-8 for analyzing FQs in complex matrices.