Development of an aflatoxin B1 specific molecularly imprinted solid phase extraction sorbent for the selective pre-concentration of toxic aflatoxin B1 from child weaning food, Tsabana

This paper presents the synthesis, optimization and application of a molecularly imprinted polymer (MIP) sorbent for the selective extraction and pre-concentration of the potent toxin, aflatoxin B1 (AFB1), from the child weaning food, Tsabana (manufactured in Serowe, Botswana). As a food safety regulatory measure, Tsabana must be cleared of hazardous aflatoxins, especially AFB1, before consumption. This is because AFB1 is the most common and potent of the aflatoxins commonly found in cereals. Accurate analysis of AFB1 is challenging because it exists in very low concentrations in complex, ‘dirty’ matrices such as food, making it difficult to detect using analytical instruments, even if these analytical techniques have sensitivities at the femto level. The MIP extraction sorbent synthesized in this paper deals with these challenges by selectively pre-concentrating AFB1 from real Tsabana samples, successfully achieving a pre-concentration factor of 5 and therefore significantly increasing ABF1 signal intensity for easier detection. Further advantages of this system include the short time (25.0 minutes) and reasonable optimal MIP dose (20.0 mg) needed for maximum AFB1 extraction by the sorbent. Scanning electron microscopy revealed that the prepared AFB1 powder particles have spherical geometries and reasonably small sizes (800 nm), two advantageous physical characteristics that are associated with excellent sorbent materials.