Adsorptive removal of aflatoxin B 1 from water and edible oil by dopamine-grafted biomass chitosan–iron–cobalt spinel oxide nanocomposite: mechanism, kinetics, equilibrium, thermodynamics, and oil quality

• Published in: RSC advances 2023-11, Vol.13 (49), p.34739-34754
• Main Authors: Abasi, N., Faraji, A. R., Davood, A.
• Format: Article
• Language: English
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/D3RA06495F

Currently, the use of magnetic physical adsorbents for detoxification is widely applied in the food industry; however, the fabrication of high-efficiency low-cost absorbents without damaging the nutritional quality of food is a major challenge. Herein, a simple, green, efficient, and cost-effective method for the magnetic solid-phase extraction of aflatoxin B 1 (AFB 1 ) from edible oils and aqueous matrices was developed using a dopamine-loaded biomass chitosan–iron–cobalt spinel oxide nanocomposite (DC/CFOS NC). The characterization, physicochemical processes, mechanism, and reusability of DC/CFOS were systematically evaluated in detail. It was found that the adsorption characteristic of DC/CFOS NC was accurately represented by the pseudo-second-order kinetics ( k 2 = 0.199 g mg −1 min −1 ) and Freundlich isotherm models ( K f = 1.139 (mg g −1 ) (L mg −1 ), R 2 = 0.991)), and its adsorptive process is feasible, spontaneous, and exothermic. Benefiting from its high specific surface area, microporous structure, and polar/non-polar active sites, the as-prepared DC/CFOS exhibited an excellent adsorption performance for AFB 1 (50.0 μg mL −1 ), as measured using the Freundlich isotherm model. The mechanistic studies demonstrated that the synergistic effects of the surface complexation and electrostatic interactions between the functional groups of DC/CFOS NC and AFB 1 were the dominant adsorption pathways. Besides, DC/CFOS exhibited negligible impacts on the nutritional quality of the oil after the removal process and storage. Thus, DC/CFOS NC showed sufficient efficacy and safety in the removal of AFB 1 from contaminated edible oil.