SPECTROPHOTOMETRIC DETERMINATION OF SOME 8-HYDROXYQUINOLINES AND DIBENZAZEPINES USING CERTAIN DIAZONIUM SALTS

Abstract

In this thesis two simple, rapid, reproducible and accurate spectrophotometric methods were developed involving the use of Fast Red AL salt and diazotized 4-amino-6-chloro-1,3-benzene disulphonamide (DACBS) as chromogenic reag­ ents for the analysis of 8-hydroxyquinoline derivatives, namely, oxyquinoline, chiniofon, clioquinol and iodoquinol as well as dibenzazepine derivatives, namely, clomipramine, desipramine and imipramine hydrochlorides and trimipramine maleate.

The proposed methods are based on the interaction of either Fast Red AL salt or DACBS reagent with the investigated 8-hydroxyquinolines to form intense red coloured products measured at A. < 1 in the range of 500-530 nm

Dibenzazepines give no coloured products with Fast red AL salt, while they form intense red coloured products measured at "-max(sl in the range of 519- 555 nm with DACBS reagent.

The interaction between 8-hydroxyquinoline derivatives and both reagents was performed in slightly alkaline media while DACBS reagent was interacted with dibenzazepine derivatives in strongly acidic solutions .

Effective variables such as the reagents concentration, pH variation, reaction and stability times and diluting solvents were studied and perfectly optimized to permit the development of simple, accurate and reproducible spectrophoto­ metric methods for the analysis of all the studied drugs.

The stoichiometry of the reaction was investigated using Job's method of continuous variation and was found to be1:1 for all the studied drugs.