Molecularly imprinted solid phase extraction coupled to high performance liquid chromatography for determination of aflatoxin M1 and B1 in foods and feeds

Abstract

A molecularly imprinted polymer was synthesized by a miniemulsion polymerization method using aflatoxin B₁ as the molecular template, methacrylic acid (MAA) as the functional monomer, ethylene glycol dimethacrylate as the cross-linker, Span80 and hexadecyl trimethyl ammonium bromide as the surfactants and n-hexadecane as the hydrophobic reagent in the presence of water. This imprinted polymer was characterized by FT-IR, ¹H NMR, scanning electron microscopy, laser light scattering and adsorption experiments, in which the results showed good recognition and selectivity to aflatoxin B₁ and M₁. Using the prepared polymer as a solid phase extraction sorbent, a highly selective sample pre-treatment method combined with high performance liquid chromatography and fluorescence detection was developed for determination of aflatoxin B₁ and M₁ in foods and feeds. The limit of detection and limit of quantification of this method for aflatoxins M₁ and B₁ were 0.05 μg kg⁻¹ and 0.16 μg kg⁻¹, respectively. The average recovery values from barley, peanut oil, feed and beer spiked samples ranged from 83% to 96%. The precision ranged from 2.2% to 5.6% for these samples. The proposed method was found to be more effective and economical as a pre-treatment technique than regulation 2006/40/EC.