Determination of mercury traces in products of TiO2 manufacturing

A simple method far the determination of mercury traces in co-products and final products of titanium (IV) oxide manufacturing was developed. It was s hown that different procedures recommended for the total digestion of such materials (using mixtures of HF HNO3, HCl and HClO4) could be efficiently r eplaced by an unique partial digestion method based an mercury leaching fro m sample by HNO3. Partial digestion method was much quicker and more sensit ive than total digestion methods. Mercury was detected with cold vapour ato mic fluorescence spectroscopy and a detection limit of 10 pgHg/g was achiev ed. The method was validated using certified reference materials PACS-1 (NR CC) and maroccan phosphate rock (BCR). Regarding mercury content in analyse d samples from the point of view of the ecological risk, only residual mate rial after first digestion of raw material with H2SO4 were found to contain mercury concentrations higher than accepted background value for sediment and soils (0.1 mu gHg/g). All other cc-products as well as the final produc t titanium (TV) oxide were almost free of mercury (<0.01 - 30 ngHg/g).