RESUMO
A simple and sensitive spectrophotometric method is developed for the determination of titanium in aqueous medium. The metal ion forms a reddish brown coloured complex with 2,4-dihydroxybenzaldehyde isonicotinoyl hydrazone (2,4-DHBINH) in the pH range 1-7. The complex shows two absorption maxima, one at 430 nm and the other at 500 nm. The reagent shows appreciable absorbance of 430 nm and negligible absorbance at 500 nm at pH 1.5. Beer's law is obeyed in the range 0.09 to 2.15 mug ml(-1) of titanium(IV). The molar absorptivity and the Sandell's sensitivity of the method are 1.35 x 10(4) 1 mol(-1) cm(-1) and 0.0049 mug cm(-2), respectively. A method for the determination of titanium by first-order derivative spectrophotometry is also proposed. The methods have been employed successfully for the determination of titanium in several alloy and steel samples.
