Spectrophotometric determination of titanium in steel with 4-(2-thiazolylazo)-1, 2, 3-trihydroxybenzene

The chromogenic reaction of titanium(IV) with the reagent 4-(2-thiazolylazo)-1, 2, 3-trihydroxybenzene (TATB) has been studied spectrophotometrically in the presence of CTMAB in detail. The results show that in the medium of ClCH2COOH-ClCH2COONa buffer solution at pH 2.0-5.0, Ti(IV) reacts with the reagent TATB to form a stable red complex with the molar ratio of n (Ti(IV)):n (TATB)=1:2. The maximum absorption of the complex is at 560 nm with an apparent molar absorptivity of 4.07 × 104 L·mol-1·cm-1. Beer's law is obeyed in the range of 0-20 μg/25 mL for Ti(IV). The proposed method has been applied to the determination of titanium in steel samples, and the results are in agreement with the certified values.