Title : "Sequential Determination of Ti(III) and Ti(IV) by Flow Injection Spectrophotometry"

Researcher : Kate Grudpan, Pattanapong Aumpun. Jaroon Jakmunee and Gary D. Christian

Office of Researcher : CHEMISTRY


Sequential determination of Ti(III) and Ti(IV) is proposed using a FI manifold. A mixture (standard/sample) of Ti(III) and Ti(IV) is injected into a stream of acidic Fe(III) solution whereby redox taking place before merging into a thiocyanate stream. Ti(III) reduces Fe(III). The intensity of the colored Fe(III)-thiocyanate complex then decrease and monitored continuously at 450 nm. The decrease will be related to the amount of Ti(III). By switch a three-way value for a stream of hydrogen peroxide, another injection of the mixture will allow Ti(III) to be converted into Ti(IV). Ti(IV) (both the converted one and the Ti(IV) in the original mixture) forms a yellow complex with hydrogen peroxide. The signal will correspond to the total Ti. By difference, the amount of Ti(IV) can be evaluated. Optimization of the system will be discussed.

Presented at 10th International Conference of Flow Injection analysis (ICFIA 99), Chales University, Prague, Czech, 19-26 June, 1999.