Síntese e caracterização de MIP a partir da fenilalanina visando sua aplicação na técnica de extração em fase sólida

Abstract

Polymers Molecularly Imprinted (MIPs) were synthesized and characterized for use in extraction technique in solid phase (SPE), to the determination of phenylalanine (Phe). The MIPs are synthesized from methacrylic acid, phenylalanine, ethylene glycol dimethacrylate, 2,2-azobisisobutironitrila in chloroform. Non Imprinted Polymers (NIPs) were synthesized for control for the selectivity of MIPs. In this study we varied the ratio "mold molecule / functional monomer" in order to optimize the conditions of synthesis that occurred at 4 ° C under UV irradiation. The desorption of phenylalanine was carried out in Soxhlet extractor for 64 hours and the monitoring via reading in UV-Vis spectrophotometer. Syntheses were carried out 10, 8 MIPs and 2 NIPs. Of these, 3 MIPs were chosen as study object for presenting proportions template molecule: functional monomer more MIPs applied to the extraction technique in solid phase. The MIPs and NIPs were characterized by the following analytical techniques: FTIR, UV-Vis, SEM, DSC and TG. Not only analyzed the reaction products, but also the monomers and the template molecule. The MIPs were also evaluated for their adsorption capacity compared to the NIPs for use in SPE. Among the synthesized and evaluated MIPs, two had good adsorption capacity of phenylalanine, an average degree of adsorption between 54 and 56%. Comparing them to NIPs, which achieved the adsorption degree of around 11,7%, it was concluded that these MIPs showed up specific to the determination of Phe. MIPs avaliated by SEM showed more porous surface before extraction process, an important feature for use in SPE. The thermal stability of the MIPs, investigated by thermal analysis, showed that they can be applied as a sorbent for different sample types, since they are stable up to the temperature of 200°C. The synthesized MIP in the present study showed great potential for use in SPE technique.