Rapid CE-UV evaluation of polypyrrole-coated magnetic nanoparticles for selective binding of endocrine disrupting compounds and pharmaceuticals by aromatic interactions

Abstract

Endocrine disrupting compounds (EDCs) and pharmaceuticals in water have negative impacts on human health and environmental ecology. Sorbents that can selectively remove these compounds based on their chemical functionality would have a significant health benefit to humans and wildlife. In this work, polypyrrole-coated magnetic nanoparticles (MNPs@PPy) were evaluated as a sorbent for extraction and preconcentration of bisphenol A (BPA), metformin (MF), naphthalene acetic acid (NAA), phenformin (PF) and triclosan (TC). Both in-capillary and in vitro binding efficiencies were determined using capillary electrophoresis with ultraviolet detection (CE-UV). In-capillary binding efficiencies of 99 ± 1% were found for BPA, PF and TC, which were confirmed by in vitro binding tests. Apparently, MNPs@PPy bound strongly with aromatic compounds due to π–π bonding interactions. A mixture of ethyl acetate and methanol (75 : 25 v/v) was evaluated as the eluting solvent. CE-UV analysis determined the % recoveries to be 85 ± 13% for MF and PF which were adequate for analyte preconcentration by this method. A new coating of PPy was successfully added on the used particles for regeneration of their surfaces to achieve a binding efficiency of as high as 94 ± 3%.