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.

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@FeO) nanocomposites as the capturing absorbents. Here, the prepared TUF@FeO with the large-surface-area mesoporous structure and strong Pb-binding ligands could facilitate the selective and large-scale adsorption of Pb ions from the complex sample matrices to be further magnetically separated onto the magnetic electrodes. Moreover, the Pb ions magnetically accumulated were electrochemically measured alternatively by the solid state-based anodic stripping of PbCl. The detection limit was found to be 0.0070nmolL. The as-developed Pb electroanalysis method with the magnetic electrodes and TUF@FeO nanocomposites could avoid the complicated sample preparation and electrode modification, thus holding the great potential of applications for the Pb detection in different real samples.