Kinetic spectrophotometric determination of ruthenium based on the catalytic effect of ruthenium on the oxidation of aniline blue,water soluble by potassium periodate

A new catalytic spectrophotometric method for the determination of trace ruthenium based on its catalytic effect on the oxidation of aniline blue, water soluble(ABWS)by potassium periodate in H_2SO_4 medium was reported. A linear relationship was obtained between the difference of absorbance and concentration of Ru in the range of 0.002-0.035 μg/10 mL. The detection limit of Ru was 3.25×10~ -11 g/mL. The standard deviation for the determination of 0.020 μg/10 mL of Ru was 0.34%(n=11). The catalytic reaction was found to be first-order and zero-order for Ru and ABWS respectively, with the apparent activation energy of 35.86 kJ/ mol. Test for the interferences of more than 40 foreign ions showed that most of the common ions were tolerable. The method has been applied to the determination of Ruin noble metal concentrate with satisfactory results.