Use of itaconic acid-based polymers for solid-phase extraction of deoxynivalenol and application to pasta analysis

摘要

Molecular modelling and computational design were used to identify itaconic acid(IA)as a functional monomer with high affinity towards deoxynivalenol(DON),a Fusarium-toxin frequently occurring in cereals.IA-based polymers were photochemically synthesised in dimethyl formamide(porogen)using ethylenglycol dimethacrylate as cross-linker and 1,1'-azo-bis(cyclohexane carbonitrile)as initiator,and the relevant binding interactions with DON in solvents with different polarity were investigated.The performances of the non-imprinted IA-based polymer(blank polymer,BP)and the corresponding molecularly imprinted polymer(MIP)were compared using DON as a template.Both BP and MIP were able to bind about 90% DON either in toluene,water or water containing 5% polyethylene glycol.Non-imprinted polymers with different molar ratios of IA to cross-linker were evaluated as adsorbents for solid-phase extraction(SPE)clean-up and pre-concentration of DON from wheat and pasta samples prior to HPLC analysis.Samples were extracted with PBS/0.1 M EDTA solution and cleaned up through a cartridge containing blank IA-based polymer.The column was washed with PBS(pH 9.2)and the toxin was eluted with methanol and quantified by reversed-phase HPLC with UV detector(gamma=220nm),using methanol:water:acetic acid(15:85:0.1,v/v/v)as the mobile phase.Effective removal of matrix interferences was observed only for pasta with DON recoveries higher than 70%(RSD<7%,n=3)at levels close to or higher than EU regulatory limit.