Materials Institute Lavoisier-68(Al)-coated Frosted Glass Rods for Enhanced Detection of Tetracyclines in Food Samples by Suspended Bar Sorptive Extraction

Herein, we present a sensitive analytical method utilizing Materials Institute Lavoisier (MIL)-68(Al)-coated frosted glass rods (MIL-68(Al)@FGR) coupled with ultra-high-performance liquid chromatography for detecting trace tetracycline (TC) antibiotics in food matrices. The synthesized coating was thoroughly characterized through field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, and Fourier-transform infrared spectroscopy analyses. Systematic optimization of critical parameters, including extraction time, sample pH, formic acid concentration, and desorption time achieved optimal extraction efficiency. The developed method exhibited a wide linear range (3–70 ng/mL) with low detection limits (0.1–0.3 ng/mL) for target analytes. Practical application to spiked food samples demonstrated satisfactory recoveries of 75.2%–115.1% across milk, chicken, and egg matrices, accompanied by precise relative standard deviations of ≤8.4%. The MIL-68(Al)@FGR-based approach shows exceptional resistance to matrix interference and detection sensitivity, establishing an effective strategy for monitoring TC residues in complex food samples.