Boron-doped activated carbon nanocomposite as a selective adsorbent for rapid extraction of aflatoxins in nut samples

Activated carbon-boron (AC-B) nanocomposite has been developed as a new solid-phase extraction (SPE) sorbent for the extraction and specification of aflatoxins (AFs) in nuts. Porous activated carbon was produced by the chemical activation method from potato peels, which is important biomass waste, and boron was incorporated into the structure. Fourier transform infrared spectroscopy, nitrogen adsorption-desorption, transmission electron microscopy, X-ray diffraction, and scanning electron microscopy methods were used to characterize the adsorbent. The BET specific surface area of AC-B was found to be 1014.7 m2 g−1and the pore volume was 0.42 cm3 g−1. After the extraction parameters (adsorbent amount (1–20 mg), vortex time (1–10 min), pH (3–8), desorption solvent, desorption volume (1–10 ml), and desorption time (1–10 min)) were optimized, recoveries in the range of 89.5–96.5 % of AFG1, AFG2, AFB1, and AFB2 were obtained in real pistachio, cashew nut, and walnut samples. The highest recoveries of AFs were obtained under conditions with AC-B adsorbent amount of 5 mg, vortex time of 3 min, pH 5, desorption solvent acetonitrile, volume 3 ml, and time 3 min. AFs have a low detection limit range (0.04–0.16 μg kg−1). In addition, the method had good repeatability (the intra-day and inter-day RSDs were 0.3–7.0 %, n = 8) and was validated with CRM. The results were evaluated statistically. The proposed AC-B/SPE method has been presented as an alternative to routine analysis due to its advantages such as being environmentally friendly, simple, faster, sensitive, reliable, selective, reproducible, and ease of application in the extraction of aflatoxins compared to the traditional immunoaffinity column method.