Determination of metal impurities in titanium dioxide using slurry sample introduction by axial viewing inductively coupled plasma optical emission spectrometry

Abstract

A slurry sample introduction technique for the analysis of TiO₂ powders by axial viewing ICP-OES is reported. Relationships between stable slurries and the conditions, such as particle size, pH, dispersant and its amount, were experimentally investigated. Slurries were prepared by mixing the TiO₂ powder with the dispersant poly(acrylate amine) (NH₄PAA) and agitation in an ultrasonic bath to ensure good dispersion. The pH of the medium and amount of dispersant has been optimized. Impurities in TiO₂ were determined by an axial viewing ICP-OES spectrometer. As representatives, a Standard Reference Material 154 b of µm particle size TiO₂ and a nm particle size TiO₂ were selected and determined for micro and trace impurities. Analytical results obtained via slurry sample introduction were compared with those via nebulization of aqueous solutions prepared by acid digestion and fusion digestion. The determined results by slurry introduction were in good accordance with the stated values, which verified that the calibration curves could be established by aqueous standards.