Spectrophotometric determination of dissolved titanium in sea water after sodium diethyldithiocarbamate pre-concentration

Abstract
A simple and rapid method for the determination of dissolved titanium in sea water is described. Using sodium diethyldithiocarbamate as precipitant, titanium, iron(III), zinc and part of the magnesium and calcium ions that are naturally present in sea water are coprecipitated. After collecting the precipitate by filtering through a 0.45-µm Metricel membrane filter, the qualitative recovery of titanium and the coprecipitation of titanium with other ions were studied by X-ray fluorescence spectroscopy. The precipitate was easily dissolved in dilute hydrochloric acid and then a sensitive 4,4′-diantipyrylmethane-thiocyanate extraction method was applied, followed by spectro-photometric determination of titanium. The concentration of dissolved titanium in Tong Shiau sea water was found to be 0.11 µg l–1 with a relative standard deviation of 5%.