Design of hyper-cross-linked polymers with tunable polarity for effective preconcentration of aflatoxins in grain

Aflatoxins (AFs) as a category of polar mycotoxins possess a significant threat to human health. However, constructing of sorbents with suitable polarity for the preconcentration of AFs remains poorly developed due to the difficulty in tuning the polarity of the sorbents optionally. Herein, a series of novel hypercrosslinked polymers (OP-HCPs) with adjustable polarity were designed and synthesized by varying selection of alkylphenol ethoxylates monomers and benzyl halides crosslinkers for the preconcentration of AFs. By integration of magnetism into OP-HCP, a novel magnetic sorbent (M-OP10-DCX) was prepared to readily pre-concentrate of AFs from rice and maize samples prior to high performance liquid chromatography-fluorescence detection (HPLC-FD). Benefiting from the unique polarity interaction between M-OP10-DCX and AFs, the M-OP10-DCX displayed excellent adsorption ability for the AFs. Good linearity in the range of 5.0–4000 pg g−1 (R2 > 0.9983), low limits of detection (signal-to-noise ratio of 3) of 1.5–50 pg g−1 and high enrichment factors of 105–205 were achieved. The recoveries of the method ranged from 82.8 % to 115 % with the relative standard deviation less than 8.0 %. This work provided a new strategy for the rational design of HCPs with tunable polarity as valuable tools for specific adsorption of different kinds of compounds.