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RESEARCH PRODUCT

Design d'un iprodione-MIP (molecularly imprinted polymer) : application à la pré-concentration des fongicides dans le vin

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The aim of this study was the synthesis of a MIP (molecularly imprinted polymer) specific for a fungicide that is found in the majority of the french wine: iprodione. The challenge for extracting iprodione from wine medium was that the hydoralcoholic solution is a dipolar solvent, whereas the interaction between the MIP and iprodione is based on dipolar interactions. The first extraction study of iprodione was made on a MIP synthesized by bulk polymerization using methacrylamide and ethylene glycol dimethacrylate (EGDMA). The MIP was found to be more efficient than the NIP (non-imprinted polymer) in hydroalcoholic solutions which demonstrates that the molecular imprinting was successful. Then we synthesized 8 MIPs and 8 NIPs following an 23 experimental design in order to study the influence of three synthesis factors (the polymerization method, the nature of the crosslinker and the type of the functional monomer) on the iprodione recognition properties of the polymers. The water and the iprodione adsorption isotherms for MIPs and NIPs were determined. The result showed significant differences between the polymers involving a relationship between the water adsorption and the adsorption of iprodione. The molecular imprinting has been demonstrated by several techniques such as the differential scanning calorimetry and the nuclear magnetic resonance. The best recognition properties of iprodione are obtained with the MIP which was synthesized by precipitation polymerization using methacrylamide as functional momonomer and EGDMA as crosslinker. This MIP was used in solid phase extraction (SPE) for pre-concentration of iprodione in a white wine with a pre-concentration factor of 6. Its selectivity versus two fungicides: procymidone and pyrimethanil has been demonstrated.