Cloud point extraction and ICP-MS for titanium speciation in water samples

Abstract

An analytical method for the separation and determination of titanium dioxide nanoparticles in water samples has been developed. The separation was performed by Cloud Point Extraction (CPE) with Triton X-114. Titanium dioxide nanoparticles and ionic titanium were analysed in the surfactant rich phase and surfactant poor phase respectively, by inductively coupled plasma-mass spectrometry (ICP-MS). Parameters related to the CPE procedure such as Triton X-114 and NaCl concentrations were evaluated. Optimum concentrations of 0.03% (w/v) and 2.5 mM of Triton X-114 and NaCl respectively, were selected to develop this study. The TiO2 nanoparticles extracted were digested using HNO3 and H2O2 in an ultrasonic bath for 10 min at 60°C and analysed by ICP-MS. The analytical characteristics of the method (calibration, limits of detection and quantification, precision and recovery) were evaluated. The LOD and LOQ for Ti determination in the surfactant rich phase were 0.13 and 0.45 µg L−1, respectively. Finally, the method was applied for the determination of TiO2 nanoparticles in swimming pool water samples