An innovative method for synthesis of imprinted polymer nanomaterial holding thiamine (vitamin B1) selective sites and its application for thiamine determination in food samples.

Thiamine is a highly hydrophilic vitamin which is insoluble in common organic solvents, utilized traditionally for synthesis of molecularly imprinted polymer. In this work a simple strategy is introduced to overcome the insolubility problem of thiamine and prepare an efficient MIP in chloroform. Thiamine, as a cationic agent, involved in an ion-pair complex with anionic species of trimethylsilyl-propane sulfonate (TPS). The ion-pair was then transferred effectively to apolar solvent of chloroform where the polymerization reaction was conducted to produce nano-sized thiamine imprinted polymer. The experimental conditions such as pH, ionic strength and carrier agent/thiamine mole ratio were optimized to maximize the thiamine amount, transported to chloroform. The characteristics of the polymer were investigated by FT-IR, SEM and Zeta potential analysis techniques. The experimental adsorption isotherms of thiamine onto MIP and non-imprinted polymer (NIP) were determined and well fitted by Langmuir-Freundlich model. Maximum binding capacities of the MIP and NIP materials were obtained as 106.1 and 35.7 μmol g-1, respectively. After investigation and fixing of the experimental conditions on thiamine extraction by the MIP, it was successfully utilized for thiamine extraction from food samples and its determination by fluorimetric method.