Synthesis of GO-SiO₂/ZnO/Fe₃O₄ nano adsorbent for preconcentration of aflatoxins in food samples using SPE-HPLC-FLD...

This study demonstrates a new extraction method for determination of aflatoxins (AFs) in food samples by a GO-SiO₂/ZnO/Fe₃O₄ nanocomposite as new and effective sorbent. The nanocomposite structure was confirmed by FT-IR, XRD, EDX, FE-SEM, TEM, and mapping techniques. Optimization of the extraction process was conducted by investigating pH, adsorbent amount, sample volume, and solvent volume using central composite design (CCD). The method showed good linearity for AFs B₁, B₂, G₁, and G₂ within specified ranges. Detection and quantification limits were 0.06-0.53 and 0.20-1.62 ng mL^-1, respectively. The high performance liquid chromatography with fluorescence detector assisted by solid phase extraction (SPE-HPLC-FLD) method was applied to food samples, achieving recoveries of 70.15-97.08 %. Accuracy was confirmed through recovery measurements in spiked samples, with ranges of 70.15-97.85 % in wheat, 70.01-91.97 % in chickpeas, and 71.29-93.92 % in white pepper. Reusability and cost-effectiveness suggest its potential for preconcentration and determination of AFs in food samples.