ANALYTICAL APPLICATIONS OF IODIDE AND OSMIUM CATALYZED REACTION BETWEEN CERIUM(4) AND ARSENIC(3)

The iodide and osmium catalyzed reaction between Ce(IV) and As(lll) has been utilized for a variety of analyses. Iodide and osmium are determined separately and in mixtures without prior separation using Hg(ll) masking of iodide activity, lodide is determined in the presence of iodate by taking advantage of the fact that iodate is inactive as a catalyst. Both iodide and iodate are determined by reducing iodate to a catalytically active form using As(III). Silver(I) and mercury(II) are determined utilizing their inhibitions of the iodide catalyzed reaction. All analyses are performed at concentrations down to 10-8M with osmium being determined at concentrations down to 3 × 10−10M. Most relative errors and standard deviations are in the range of 2%. © 1969, American Chemical Society. All rights reserved.