APPLICATION OF THE REACTION OF PROMAZINE HYDROCHLORIDE WITH CHROMIUM(VI) IN VOLUMETRIC AND SPECTROPHOTOMETRIC ANALYSIS

Abstract

ABSTRACT Promazine hydrochloride (PMH) reacts in acidic medium with K2Cr2O7 forming coloured oxidation product. This property is exploited for using PMH as redox indicator in chromatometry. The spectra of oxidation products of PMH in UV and IR regions were recorded. The optimal conditions for the formation of these products and their electrochemical behaviour are described. K2Cr2O7 precipitates PMH from aqueous solutions as ion-association compound. The compound is sparingly soluble in water but can be quantitatively extracted into ethyl acetate. The extraction constant of this compound is determined and the extractive spectrophotometric method for the determination of PMH in pharmaceuticals is elaborated.