Nanometer-size titanium dioxide microcolumn on-line preconcentration of trace metals and their determination by inductively coupled plasma atomic emission spectrometry in water

A new method using a microcolumn packed with nanometer TiO₂ as solid-phase extractant has been developed for the simultaneous preconcentration of trace amounts of Cu, Mn, Cr and Ni prior to their measurements by inductively coupled plasma atomic emission spectrometry (ICP-AES). Effects of pH, sample flow rate and volume, elution solution and interfering ions on the recovery of the analytes have been investigated. The adsorption capacity of nanometer TiO₂ was found as 0.108, 0.149, 0.039 and 0.034 mmol g⁻¹ for Cu, Cr, Mn and Ni, respectively. The separation of analytes can be achieved from water samples with a concentration factor of 50 times. The method has been applied for the determination of trace elements in biological sample and lake water with satisfactory results.