Cu@Co@Ag nanoflower-assisted dispersive solid-phase microextraction for trace determination of tetracycline in food...

In this study, a novel dispersive solid-phase microextraction (D-μSPE) method based on trimetallic Cu@Co@Ag nanoflower (NF) structures was developed for the sensitive and selective determination of tetracycline (TC) in various sample matrices. Extensive optimization studies were conducted to establish the optimal extraction conditions, including the sample pH, sorbent dosage, adsorption and desorption times, and type, concentration and volume of the eluent. The synthesized NF sorbent was thoroughly characterized using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD), which confirmed its well-defined flower-like morphology and functionally active surface features. Furthermore, Brunauer-Emmett-Teller (BET) analysis was performed to confirm the specific surface area and porosity of the synthesized NFs while zeta potential analysis was performed to evaluate the surface charge characteristics of them. Under optimized conditions, the method demonstrated excellent analytical performance, achieving a high preconcentration factor of 71.4 and a strong linear response. The limits of detection (LOD) and quantification (LOQ) were determined to be 1.70 μg/L and 5.80 μg/L, respectively, indicating high sensitivity and suitability for trace-level analysis. The practical applicability of the proposed method was validated through recovery studies performed on model solutions, drinking water, tap water, and milk samples spiked with TC. The high recoveries confirmed the high precision, reproducibility, and robustness of the method across complex matrices. These results underscore the potential of the NF-based D-μSPE approach as a reliable, efficient, and cost-effective analytical tool for monitoring antibiotic residues in environmental and food samples.