Abstract
When Sb (V) is added to a mixture of fluotitanic acid and hydrogen peroxide, titanium ions, corresponding to the more stable fluoantimonic acid formed, are released, and converted to teh colored substance pertitanic acid by the action of the hydrogen peroxide present. As the color intensity is proportional to the concentration of Sb (V), a straight standard line is obtained in a certain range of Sb (V) quantity. As a reagent, a 2.5N HCl solution of mol-ratio, Na2TiF6: NaF: H2O2=1:4:1, and of 0.1M concentration with respect to titanium, was found to be suitable. Good results were obtained when the color reaction was carried out in a 2.5N HCl solution. Since the color reaction takes place almost instantaneously at ordinary temperatures, and the color being stable, this method is suited to the colorimetric determination of Sb (V) of more than micro-quantity. All reaction apparatuses, reagent vessels, and colorimetric cells used were made of plastic.
