Determination of Aflatoxin B1 in Vegetable Oils Using Low-temperature Clean-up Combined with Immunomagnetic Solid-phase Extraction

Introduction: Aflatoxins are secondary metabolites predominately produced by the fungi groups Aspergillus flavus and Aspergillus parasiticus, which widely contaminate agriculture produce and are transferred into vegetable oils during manufacturing process. Since the toxicity of aflatoxin B1 (AFB1) has raised concerns and vegetable oils are an important component of our daily diet, the accurate detection of AFB1 in vegetable oils is necessary and critical.

Purpose: This stuy developed a highly convenient and sensitive method to detect AFB1 in vegetable oils.

Methods: Antibody functionalized magnetic nanoparticles were synthesized and applied for the immuno magnetic solid phase extraction of AFB1 in vegetable oils after low temperature clean-up. The analyte in the extract was quantified using HPLC hyphenated with a fluorescence detector afterwards.

Results: Antibody functionalized magnetic nanoparticles were successfully synthesized and applied to extract the AFB1 in five kinds of oils (corn, canola, peanuts, soybean, and olive oil). The average diameter of Fe₃O₄ nanoparticles was 11.4±3.5 nm. The saturation magnetic moment of Fe₃O₄ nanoparticles and ammonia group functionalized nanoparticles were 48.9 and 33.1 emu/g, respectively. The calibration curve for quantifying AFB1 was successfully built with R²value of 0.9957, suggesting acceptable linearity of the method applied. Interestingly, none of the oil samples tested were contaminated with AFB1 in the present study.

Significance: The results suggested that the proposed method is promising for detecting trace amount of AFB1 in vegetable oils.