On-line preconcentration of ultra-trace thallium(I) in water samples with titanium dioxide nanoparticles and determination by graphite furnace atomic absorption spectrometry

Abstract

A new method has been developed for the determination of Tl(I) based on simultaneous sorption and preconcentration with a microcolumn packed with TiO2 nanoparticle with a high specific surface area prepared by Sonochemical synthesis prior to its determination by graphite furnace atomic absorption spectrometry (GFAAS). The optimum experimental parameters for preconcentration of thallium, such as elution condition, pH, and sample volume and flow rate have been investigated. Tl(I) can be quantitatively retained by TiO2 nanoparticles at pH 9.0, then eluted completely with 1.0 mol L−1 HCl. The adsorption capacity of TiO2 nanoparticles for Tl(I) was found to be 25 mg g−1. Also detection limit, precision (RSD, n = 8) and enrichment factor for Tl(I) were 87 ng L−1, 6.4% and 100, respectively. The method has been applied for the determination of trace amounts of Tl(I) in some environmental water samples with satisfactory results.