Molecularly imprinted polymer with mixed-mode mechanism for selective extraction and on-line detection of ochratoxin A in beer sample

Abstract

In this work, a novel molecular imprinted polymer (MIP) was prepared with “one-pot” process using acrylamide-2-methylpropanesulfonic acid (AMPS) as the functional monomer and ochratoxin A (OTA) as the template molecule. The morphology and structure of the resulted MIP were characterized, and its adsorption performance and mechanism for the analytes were also investigated. The results showed that the recovery of MIP for OTA was 84.8%, while that of non-imprinted polymer (NIP) was only 4.5%. Moreover, the recovery ratio of OTA to ochratoxin B (OTB) on MIP was 74.4 at pH 8.5, even though OTB content was 100 times as much as OTA content in the mixture of mycotoxins. The limit of detection of this method based on MIP combined with high performance liquid chromatography-fluorescence detection (HPLC-FLD) for OTA was 0.07 ng mL−1, which was lower than 2 ng mL−1 from the European Union limit for beer. The spiked recoveries of OTA were in the range of 95.0 ± 1.5%–97.1 ± 3.1%, which showed that the obtained MIP had great potential to be applied as a specific adsorbing material for mycotoxins in complex samples.