Development and Validation of an Automated Magneto-Controlled Pretreatment for Chromatography-Free Detection of Aflatoxin B in Cereals and Oils through Atomic Absorption Spectroscopy.

A chromatography-free detection of aflatoxin B (AFB) in cereals and oils through atomic absorption spectroscopy (AAS) has been developed using quantum dots and immunomagnetic beads. A magneto-controlled pretreatment platform for automatic purification, labeling, and digestion was constructed, and AFB detection through AAS was enabled. Under optimal conditions, this immunoassay exhibited high sensitivity for AFB detection, with limits of detection as low as 0.04 μg/kg and a linear dynamic range of 2.5-240 μg/kg. The recoveries for four different food matrices ranged from 92.6% to 108.7%, with intra- and inter-day standard deviations of 0.7-6.3% and 0.6-6.9%, respectively. The method was successfully applied to the detection of AFB in husked rice, maize, and polished rice samples, and the detection results were not significantly different from those of liquid chromatography-tandem mass spectrometry. The proposed method realized the detection of mycotoxins through AAS for the first time. It provides a new route for AFB detection, expands the application scope of AAS, and provides a reference for the simultaneous determination of multiple poisonous compounds (such as mycotoxins and heavy metals).