Spectrophotometric determination of aflatoxin B1 in food sample: Chemometric optimization and theoretical supports for reaction mechanisms and binding regions

A green, simple, and cheap analytical approach for extraction, preconcentration, and determination of aflatoxin B1 (AFB1) in food samples based on vortex-assisted room temperature ionic liquid-based microextraction (VA-RTIL-ME) was presented. Important parameters including pH, metal amount, ligand amount and vortex time were optimized by using Box-Behnken design. At pH = 5.6, a ternary complex between Zn(II), fluorescein and AFB1 was formed, and extracted into the fine droplets of Tri-n-butyl phosphate (room temperature ionic liquid, extraction solvent) which were dispersed with a vortex (disperser solvent) into the extraction solution. Quantum chemical parameters and tools are widely used to predict the reaction mechanisms of interactions and binding regions of molecules. Via calculated quantum chemical parameters and energy calculations, reactions mechanisms and binding regions for studied molecules were highlighted. Under optimized conditions, linear range, limit detection, enrichment factor were 3-500 ng mL(-1), 0.9 ng mL(-1) and 140, respectively. Detailed validation studies (accuracy, precision, measurement uncertainty, selectivity, robustness..etc.) were performed under optimum experimental conditions. The good recoveries (93.9-104.3%) and low relative standard deviation (RSD%, 1.5-3.0%) were a good remark of the proposed method. For the reliability of analytical results, the results obtained with the developed method were compared with the standard ELISA test for AFB1. The developed method was successfully applied to the extraction and determination of AFB1 in food samples.