KINETIC AND APPLICATION: STUDIES ON THE REACTION SYSTEM OF OSMIUM(Ⅳ)-ARSENIC(Ⅲ)-CHLORATE

摘要

The experiments have proved that Os（Ⅳ） has very strong catalytic effect on the chlorate oxidation of As（Ⅲ） in perchloric acid media, and As（Ⅲ） exhibits a sensitive single-sweep oscillopolarographic wave at-0.75 V vs. SCE. The kinetics of this catalytic reaction has been investigated by the initial rate procedure. The mechanism has been proposed. A new and highly sensitive catalytic reaction-oscillopolarographic method for the determination of ultratrace amounts of osmium has been described, based on the Os（Ⅳ） catalytic effect on the reaction. The linear range of 5.0×10-11-4.4×10-9 mol/L and 6.0×10-9-1.3×10-7 mol/L Os was obtained using the fixed-time procedure and the initial rate procedure, respectively. Osmium in refined ore was analysed by this method.