Magnetic mesoporous thiourea-formaldehyde resin as selective adsorbent: A simple and highly-sensitive electroanalysis strategy for lead ions in drinking water and milk by solid state-based anodic stripping

Abstract

A simple and sensitive electroanalysis method has been developed for the direct determination of lead ions of nanomolar levels in real samples of drinking water and milk by employing magnetic mesoporous thiourea-formaldehyde resin (TUF@Fe3O4) nanocomposites as the capturing absorbents. Here, the prepared TUF@Fe3O4 with the large-surface-area mesoporous structure and strong Pb2+-binding ligands could facilitate the selective and large-scale adsorption of Pb2+ ions from the complex sample matrices to be further magnetically separated onto the magnetic electrodes. Moreover, the Pb2+ ions magnetically accumulated were electrochemically measured alternatively by the solid state-based anodic stripping of PbCl2. The detection limit was found to be 0.0070nmolL−1. The as-developed Pb2+ electroanalysis method with the magnetic electrodes and TUF@Fe3O4 nanocomposites could avoid the complicated sample preparation and electrode modification, thus holding the great potential of applications for the Pb2+ detection in different real samples.