Spectrophotometric determination of clioquinol and diodoquin in pharmaceutical preparations using uranyl acetate as a chromogenic agent

Abstract

Simple spectrophotometric methods for the determination of clioquinol and diodoquin in pharmaceutical preparations, based on the measurement of the intensity of the yellow-orange colour produced by the reaction of clioquinol or diodoquin with uranyl acetate in N,N-dimethylformamide (DMF) medium have been developed. The yellow-orange complex has an absorption maximum at 394 nm with molar absorptivities of 0.36 × 10³ and 0.41 × 10³ l mol^–1 cm^–1 for clioquinol and diodoquin, respectively. The method is best suited to the determination of 0–175 and 0–225 µg ml^–1 of clioquinol and diodoquin, respectively.