Spectrophotometric and fluorimetric determination of clonidine hydrochloride

Abstract

Two methods are described for the determination of clonidine hydrochloride: a simple and rapid spectrophotometric method based on the reaction of this drug with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) to form a coloured product with maximum absorption at 455 nm; and a very sensitive fluorimetric method based on the reaction of clonidine hydrochloride with 1-dimethylaminonaphthalene-5-sulphonyl chloride (dansyl chloride) to give a highly fluorescent derivative. The relative standard deviation for both methods was less than 2%. The proposed methods have been applied to the determination of clonidine in pure and in tablet form.