Evaluation of electrochemically synthesized sulfadimethoxine-imprinted polymer for solid-phase microextraction of sulfonamides

Abstract

Solid-phase microextraction (SPME) is widely used in analytical laboratories for the analysis of organic compounds, thanks to its simplicity and versatility. In the present work, the synthesis and evaluation of imprinted films for SPME by electropolymerisation of pyrrole alone or in the presence of ethylene glycol dimethacrylate is proposed. Sulfadimethoxine (SDM), a sulfonamide antibiotic, was used as template molecule. Initially, a molecularly imprinted polymer film was prepared by electropolymerisation of pyrrole onto a platinum foil, using SDM as template. The SDM template was removed by overoxidation. The behaviour of SDM on imprinted and non-imprinted polymers was investigated by differential pulse voltammetry, and a clear imprinting effect was observed, which was confirmed by rebinding experiments using both conventional and electrochemically enhanced-SPME. However, in general, the extraction efficiency was rather low (<6%) and unspecific interactions are too high. Attempts to increase extraction efficiency were unsuccessful, but the incorporation of ethylene glycol dimethacrylate to the films reduced unspecific interactions to a certain extent.

Keywords: electropolymerisation; imprinted polymers; pyrrole; solid-phase microextraction; sulfonamide antibiotics.