Vitamin C-reduced graphene oxide/Fe3O4 composite for simultaneous removal of aflatoxin B1 and benzo(a)pyrene in vegetable oils

Abstract

Vegetable oils are essential constituent of the daily dietary intake. Nevertheless, they often contain aflatoxin B1 (AFB1) and benzo(a)pyrene (BAP). Physical adsorption is the most commonly used detoxification method in the vegetable oils industry. Regrettably, the previously reported adsorbents have exhibited limited efficacy, rendering them inadequate for meeting the requirements of large-scale production of edible oils. In this work, a superparamagnetic Fe3O4/reduced graphene oxide (rGO) composite was synthesized by a one-step hydrothermal method using vitamin C (VC), and systematically characterized. The Vitamin C-reduced graphene oxide/Fe3O4 composite (VC-rGO/Fe3O4) could serve as an efficient adsorbent in edible vegetable oils for the simultaneous removal of AFB1 and BAP. The results of the batch adsorption studies indicated that the pseudo-second order model and Sips model, respectively, were the best fit kinetic model and adsorption isotherm model. The adsorption of AFB1 and BAP on VC-rGO/Fe3O4 was spontaneous, which included both physical and chemical adsorption processes. The removal efficiencies of VC-rGO/Fe3O4 in 13 vegetable oils were evaluated, revealing a wide range of practical applications. Moreover, the quality and safety of detoxified vegetable oils is acceptable. Therefore, VC-rGO/Fe3O4 have been tested as promising candidates for the simultaneous removal of AFB1 and BAP in edible vegetable oils.