RAPID SPECTROPHOTOMETRIC METHOD (AQUEOUS AND EXTRACTIVE) FOR THE DETERMINATION OF TITANIUM IN SILICATE ROCKS

A sensitive and highly selective aqueous as well as extractive spectro photometric method has been developed for the determination of titaniu m(IV) using 2,3-dihydroxynaphthalene (H2ND) as a chromogenic agent. Th e reagent (H2ND) forms a 1:3 (TiOH3+:ligand) complex at pH 4-9. The mo lar absorptivity and Sandell's sensitivity are 3.2 x 10(4) l.mol-1.cm- 1 and 0.001 mug/cm2, respectively at lambda(max) 375 nm. The method ha s been found highly selective for Ti(IV) determination in rock samples . Solvent extraction of Ti(IV) in ethylacetate greatly improves the de tection limit of the method. The method has been successfully applied to diverse silicate rock samples and results obtained are favourably c omparable with those obtained from the tiron method. The reagent (H2ND ) used in the present investigation is a much better variant than tiro n for titanium(IV) determination in silicate rock samples in terms of sensitivity, selectivity, operational simplicity and economy.