Photometric determination of titanium

The small quantities of titanium in water samples are concentrated by precipitation on iron hydroxide as carrier. Photometric determination is carried out with the aid of chromotropic acid, which forms a red chelate with titanium (IV) at pH 2 (8 approximately 17,000 at A = 70 nm). 

Titanium chelate of chromotropic acid (1,8-dihydroxy - 3,6-disulphonic acid). 

The method is suitable for the determination of titanium (IV) concentration down to about 0.02 mg/1 in water. 

Precipitation with iron hydroxide as a non-isotopic carrier has the effect that virtually no interfering matter is brought into the solution for 

Titanium (IV) readily undergoes hydrolysis and subsequently no longer reacts with chromotropic acid (G. Wiinsch). If this occurs there is not necessarily any visible indication in the form of turbidity or precipitation. The 

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Extraction-photometric determination of titanium in alloys using naphthalene-2-sulfonic acid and diantipyrylmethane was investigated [3]. No interference from large quantities of many common metals was reported. 

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