Determination of trace ruthenium（Ⅲ） by catalytic spectrophotometry in acridine yellow-potassium bromate system
WANG Ai-xiang*, MIAO Yan
Shandong Provincial Key Laboratory of Soil Conservation & Environmental Protection, School of Chemistry and Chemical Engineering, Linyi University, Linyi 276005, China
Abstract：A new catalytic spectrophotometric method for the determination of Ru（Ⅲ） was developed，based on the catalytic effect of trace Ru on the oxidation of acridine yellow by potassium bromate in the medium of sulfuric acid. The optimal experimental conditions and kinetic dynamics parameters were investigated. Under the optimal experimental conditions, Ru（Ⅲ） had a good linear relationship with absorbance difference ΔA of the catalyzed reaction and uncatalyzed one in the range of 2-20 μg/L. The coefficient of correlation was 0.998 8 with a detection limit of 5.33×10-8 g/L. Moreover, the apparent rate constant and activation energy were 4.83×10-5 s-1 and 60.69 kJ/mol，respectively. The effect of 40 coexisting ions on the determination of 10 μg/L Ru（Ⅲ） was tested. Other ions were allowed at above 10 times except the allowed amount of Th（Ⅳ），Pd（Ⅱ），Pt （Ⅳ），Rh（Ⅲ），Ir（Ⅳ） was no more than 5 times. Ru in ore and metallurgical product had been determined by proposed method combined with distilling separation,with relative standard deviation of less than 1.8 % and recovery of 98.8 %-102.3 %.
