Abstract
From 0.02 to 0.60% of titanium as an impurity in ferro-niobium was determined with diantipyryl methane as a colorimetric reagent. Titanium and niobium are similar in their analytico-chemical properties, and often interfere each other with their spectrophotometric determination. With this reagent, diantipyrylmethane, however, niobium several hundred times as much as titanium did not interfere, provided that niobium had been previously converted to its oxalate.
A sample was fused with potassium pyrosulfate, and digested into a sulfuric acid solution containing ammonium oxalate. An appropriate aliquot (corresponding to 10100 μg Ti) was taken out, and iron was reduced by adding ascorbic acid. Eight milli liters of hydrochloric acid (1+1) and 20 ml of the 1% reagent solution were added, and the whole volume was made up to 50 ml with water. The amount of titanium was obtained by the measurement of absorbance at 385 mμ after 45 minutes.
