Synthesis and Evaluation of a Molecularly Imprinted Polymer for Pre-concentration of Patulin from Apple Juice

Patulin, (4-hydroxy-4H-furo[3,2-c] pyran-2(6H)-one) is a toxic secondary metabolite produced by a wide range of fungal species growing on some fruits, including apples. A novel molecularly imprinted polymer (MIP) for patulin has been synthesized using oxindole as a dummy template. The synthesis of MIPs based on dummy templates is a solution to overcome "template bleeding" shortcoming in trace analysis. The polymer was prepared in a non-covalent approach with methacrylic acid as functional monomer and ethylene glycol dimethacrylate as cross-linker via free radical polymerization. It was revealed that the MIP particles in extraction columns displayed high affinity towards patulin and, therefore, subsequently employed for molecularly imprinted-solid phase extraction (MIP-SPE) of patulin from contaminated apple juice samples. The analysis of spiked samples showed good recoveries (> 80%). Reproducibility, repeatability, and limit of detection of the proposed method were also investigated.