Catalytic kinetic spectrophotometric determination of trace ruthenium based on its catalytic effect on the oxidation of Giemsa pigment by potassium periodate

Potassium periodate could oxidize Giemsa solution in sulphuric acid medium(resulted in fading) and ruthenium(Ⅲ) could catalyze this reaction.Based on these,a determination of trace ruthenium by catalytic kinetic spectrophotometry was established.Ruthenium showed good linearity with catalytic reaction rate in the range of 0.002-0.008 μg/mL,and the detection limit was 1.88×10-10 g/mL.This catalytic reaction was first-order reaction for ruthenium(Ⅲ) with apparent activation energy of 12.44 kJ/mol.The effect of more than 40 kinds of co-existing ions was investigated.It was found that most common ions had no interference.This method was applied to the determination of ruthenium in precious metal concentrate,and the results were in good agreement with the recommended value.The relative standard deviation(RSD) was 2.2 %-2.6 %.The average recovery of standard addition was 98 %-99 %(n=6).