A novel Fe3O4@SrTiO3@ZnO nanocomposite for simultaneous selective and efficient magnetic solid phase extraction of aflatoxins from food samples

Abstract

A novel Fe₃O₄@SrTiO₃@ZnO nanocomposite was synthesized and utilized as a magnetic solid-phase extraction (MSPE) sorbent for the efficient and selective preconcentration of trace-level aflatoxins (B1, B2, G1, and G2) in food samples. During the MSPE process, many extraction parameters such as nanocomposite amount, desorption conditions (solvent, volume, time), vortex time, and pH were optimized. Aflatoxins (AFs) in the samples were analyzed by high-performance liquid chromatography-post-column derivatization-fluorescence detection method. Under suitable conditions, the limits of detection (LODs) ranged from 0.005 to 0.015 ng g⁻¹, and the limits of quantification (LOQs) ranged from 0.016 to 0.052 ng g⁻¹.For spiked hazelnut, pistachio, and almond samples at 2 ng g⁻¹, recoveries ranged from 90.7 % to 96.6 %, while the coefficient of variation (RSD) was found to be lower than 3.1 %. The approach demonstrated excellent intra-day and inter-day repeatability (RSDs 0.006–0.071 %, n = 9). The suggested new Fe3O4@SrTiO3@ZnO/MSPE method has offers a simpler, faster, and more selective alternative with effective extraction performance in the extraction of AFs in food samples (hazelnut, peanut butter, hazelnut butter, walnut, almond, cashew, pistachio, corn, rice) checked to the classic routine immunoaffinity column method. Given its performance and operational advantages, the developed method represents a strong alternative to classical analytical approaches for routine aflatoxin determination.