Effective extraction and sensitive detection of aflatoxins in wheat by polymeric ionic liquid-based magnetic adsorbent with multiple interactions.

In this study, polymeric ionic liquids (PILs) modified magnetic nanoparticles were used to extract four aflatoxins (AFs) from wheat samples, providing a convenient and cost-effective sample preparation technique for AFs detection in the complex food matrix. The extraction parameters were optimized in terms of the amount of adsorbent, adsorption time, type and volume of desorption solvent, desorption time, and salt addition. The results showed that the proposed method had high sensitivity, good repeatability, and wide linear range. The limits of detection (S/N=3) of four AFs were 0.05-0.41 μg kg. The accuracy was also evaluated using spiked wheat samples and acceptable relative recovery of four AFs at different fortification levels were obtained, ranging from 50.3 %-110.4 %. It was indicated that both the anion species and the alkyl chain length of cation in PILs significantly affected the extraction efficiency. Meanwhile, multiple interactions, including hydrogen bonding, π-π and p-π, and hydrophobic interactions between the adsorbent and the AFs, were responsible for the effective extraction.