Spectrophotometric study of the reaction of uranium(VI) with a new salicylazochromotropic acid derivative

Abstract

On the basis of a study of substituted salicylic acid groups as functional analytical groups in the determination of uranium(VI), a new bissalicylazo-chromotropic derivative has been synthesised, i.e., the 3,6-bis(4-carboxy-3-hydroxyphenylazo)-4,5-dihydroxynaphthalene-2,7-disulphonic acid, as the tetrasodium salt. The reagent thus obtained gives a sensitive reaction with uranium(VI), which enables between 0·5 and 16 µg ml^–1 of uranium to be determined. Uranium(VI) combines with the reagent in the ratio 1:2, and the instability constant of the compound is 1·2 × 10^–9.