Electrospun nanofiber composite based on bimetallic metal–organic framework/halloysite nanotubes/deep eutectic solvents/molecularly imprinted polymers for thin film microextraction of sulfonamides in milk, eggs and chicken meat by HPLC analysis

Abstract

Herein, electrospun nanofibers based on bimetallic metal–organic framework@ functionalized halloysite/deep eutectic solvents/molecularly imprinted polymers was synthesized as new solid phase extractant for thin film microextraction of sulfacetamide, sulfamethoxazole, sulfamethazine and silversulfadiazine by HPLC-UV analysis. After synthesizing new phase through electrospinning nanofibers and thin film fabrication, we effectively leverage the synergistic properties of these materials within the composite structure. The resultant thin film nanocomposite, which integrates molecularly imprinted nanofibers, highlights the presence of inorganic nanotubes called halloysite, functionalized with a deep eutectic solvent and bimetallic metal–organic frameworks. Characterization of synthesized thin films were successfully characterized for structural, morphological, and surface analysis using infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX) and scanning electron microscopy (SEM). In this study, a syringe design was employed for the microextraction of sulfonamides (SAs) using thin film microextraction, which is carried out in two stages: adsorption and desorption, both within the syringe. The effects of several experimental conditions on desorption stage, including desorption parameters including pH, desorption solvent type, and ultrasonication time were studied by the single factor at a time. A Box-Behnken design (BBD) was applied to optimize the significant variables to obtain the optimum extraction conditions. The detection limit of the method was 0.003 µg/L and also the limit of quantification method was in the range of 0.01 µg/L. These results demonstrate the presented thin film microextraction method can serve as a good candidate for the microextraction and determination of sulfonamides in food samples like milk, eggs and chicken meat.