Determination of Trace Ruthenium(III) with Ruthenium Catalyzing Potassium Periodate Oxidizing Methyl Violet Fading Kinetic Spectrophotometric

On condition of heating to 70℃ in water bath and diluted H2SO4 used as medium,the fading reaction in potassium periodate catalyzing methyl violet can be catalyzed by ruthenium(III),and based on this phenomenon,a new catalytic kinetic spectrphotometry determination of ruthenium(III) has been founded.The optimum experimental conditions of the catalytic reaction was studied,and the absorbance difference between non-catalytic reaction and catalytic reaction remained good linear relationship with mass concentration ρ of ruthenium(III) in the range of 0.02~1.5μg/25mL at wavelength 581nm.The detection limit was 1.933×10-10 g/mL.The kinetic parameters were determined and showed that the reaction was first order to ruthenium(III) and pseudo first order to the whole reaction.The apparent rate constant was 5.967×10-4 /s,and the apparent active energy was 49.36 kJ/mol.The relative standard deviation for the determination of 1.0 μg /25mL ruthenium standard solution was 1.8%(n=11).Applied to the determination of ruthenium in molecular sieve and active carbon samples,the recovery of this method was 98.8%~102.2% which fulfilled the requirement of analysis.