Three-dimensional tree-like branched TiO 2 nanorods for the highly selective enrichment and determination of lead.

Branched titanium dioxide nanorods (B-TiO ₂ NRs) grown on fluorine-doped tin oxide glass (FTO) were developed, which can be used as a solid-phase extractant for preconcentration and determination of trace Pb(II) combined with inductively coupled plasma optical emission spectrometry (ICP-OES). The B-TiO ₂ NR-based glass substrate displayed excellent adsorptive selectivity and capacity for Pb(II); the maximum adsorption capacity was found to be 168.4 mg⋅g ^-1 PB(II) at pH = 5.0. It proved that the primary extraction mechanism was attributed to soft acid/soft base interactions to form complexes for chemisorption. Investigating the adsorption kinetics and isotherms indicated that the pseudo-second-order and Langmuir models can better describe Pb(II) adsorption on the B-TiO ₂ NRs. The proposed method presented good linearity from 0.01 to 5 mg⋅L ^-1 with a correlation coefficient (R ² ) of 0.9989 and a low limit of detection (LOD) of 2.2 μg⋅L ^-1 for Pb(II) under optimal conditions. The method was successfully applied to Pb(II) determination in foodstuffs with desirable recoveries from 93.18 to 108.1% and good precision with an RSD of less than 12.2%. This work provides a new strategy for selective extraction and determination of Pb(II) in complicated matrix samples.
(© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)