Abstract
A method for the photometric determination of 0.010.5% zirconium in iron and steel with Arsenazo III in nitric acid solution has been studied. The absorbance in the nitric acid solution is more independent on the acid concentration than in the hydrochloric acid solution. The established procedure is as follows.
One tenth g. sample is decomposed with nitric acid and hydrofluoric acid, heated and evaporated with perchloric acid to white fumes. One tenth aliquot is taken and 50 ml of nitric acid and 5 ml of 10% urea solution are added. Ten ml of 0.1% Arsenazo III solution is added to form a blue complex and the solution is diluted with water to 100 ml. Zirconium is determined from the absorbance at 665 mμ.
The determination was carried out in the presence of iron within an absolute error of 0.005%. The time required for the analysis was about 30 min. Elements commonly present in iron and steel scarcely interfered.
