Separation and preconcentration of trace indium(III) from environmental samples with nanometer-size titanium dioxide

This work assesses the potential of an adsorptive material, nanometer TiO(2), for the separation and preconcentration of trace indium ions from various aqueous media. The adsorption behavior of nanometer TiO(2) for indium ions was investigated. It was found that the adsorption percentage of the indium ions was more than 96% in pH 3.5-4.0, and the desorption percentage of In(III) ions was more than 99% in pH <= 51.5. Good relative standard deviate (1.5%) and lower analytical detection limit (0.45 mu g.mL(-1)) were obtained. The adsorption equilibrium was well described by the Langmuir isotherm model with monolayer adsorption capacity of 4566 mu g g(-1) (25 degrees C). The accuracy of the method is confirmed by analyzing the certified reference material (GBW-07405, GBW07406). The results demonstrated good agreement with the certified values. (C) 2008 Elsevier B.V. All rights reserved.