Determination of trace ruthenium (III) by catalytic kinetic spectrophotometry with crystal violet-potassium periodate system

In the H2SO4 and heated condition,discoloration reaction during potassium periodate oxidizing crystal violet can be catalyzed by ruthenium(Ⅲ).According to this phenomenon,a new method of trace ruthenium(Ⅲ) determination by catalytic kinetic spectrophotometry was established.Best experimental conditions were discussed.Difference ΔA between non-catalytic reaction absorbency A0 and catalytic reaction absorbency A remained a good linear relationship with mass concentration ρof ruthenium(Ⅲ) in the range of 0.00~0.06 μg·mL-1 and the detection limits was 1.160×10-1 μg·mL-1.Relative standard difference of 1 μg ruthenium(Ⅲ) was 1.67%(n=11).The kinetic parameter of this reaction was also determined and the result showed that the reaction was first-order reaction.The apparent ratio constant was 3.32×10-4 s-1 and apparent active energy of the reaction was 57.34 kJ·mol-1.The method was applied to the determination of trace ruthenium(Ⅲ) in molecular sieves and active carbon and the recovery ratio was between 98.4%~104.6%.