Magnetic molecularly imprinted polypyrrole as a new selective adsorbent for pharmaceutically active compounds

Abstract

In the present work, a magnetic molecularly imprinted polypyrrole (MMIPPy) was synthetized as a new selective adsorbent for pharmaceutical active compounds (PhACs) from aqueous samples. Praziquantel (PZQ) enantiomers were chosen as proof of concept in adsorption studies. To compare the selectivity of polymer, the non-imprinted polypyrrole was also synthetized. The adsorbents were characterized by XRD, FTIR, TG, SEM and EDS. The adsorption studies show that Langmuir model is the one that best represents the adsorption mechanism involving PZQ enantiomers. At pH 6.5, the adsorption of the PZQ enantiomers occurred homogeneously on the monolayer of the MMIPPy, with high values of adsorption capacity of 1322 and 1508 mg g–1, for 1-PZQ and 2-PZQ, respectively. The results provided by the Langmuir model are in agreement with the kinetic study, which also indicated the PZQ enantiomers were adsorbed rapidly (˜ 10 min) on the MMIPPy surface. The adsorption process involved an endothermic process. Furthermore, MMIPPy showed the most suitable and selective adsorbent material for PZQ enantiomers when compared to other adsorbents and PhACs.