Catalytic kinetic spectrophotometric determination of trace ruthenium(III) with potassium periodate and chlorophosphonazo-mk system

The catalytic effect of ruthenium(Ⅲ) on the oxidation decolorizing reaction of chlorophosphonazo-mk by potassium periodate in phosphoric acid medium was investigated. Based on this, the determination of ruthenium(Ⅲ) by the kinetic spectrophotometry was established.The rate equation,reaction order and apparent activation energy of the catalytic reaction were also studied.In 25 mL solution, the linear range for the determination of Ru(Ⅲ) is 0.12-1.1 μg with detection limit of 6.19×10-10 g/mL,and most coexisting ions don't interfere in the determination.The method has been applied to the determination of trace ruthenium in ores and metallurgy products and the results are consistent with the original values,the recoveries are in the range of 98.8%-101.0% with RSD no more than 2.5%.