Spectrophotometric Study of 2-Aminophenol and Catechol Via Reaction with p-Aminoacetophenone

Abstract

A simple, sensitive and selective method has been developed for the determinations of 2-aminophenol and catechol. The method is based on the reaction of 2-aminophenol and catechol with p-aminoacetophenone and dichromate at pH 5 and 4.5 were Studied. The reactions gave and an intense water soluble color products their have a maximum absorption at 506.5 , 540 nm and εmax 0.3*104 and 0.7*104 for 2-aminophenol and catechol respectively .
A linear correlations (1-9 μgml-1) for both compounds were found between absorbance at λmax and concentration. The results obtained are both precise (RSD were better than 1.9 % and 2.2 % respectively) and accurate (relative error were better than 0.47% and 0.25%) . The colored products were found to be 1:1 2-aminophenol : p-aminoacetophenon and catechol : p-aminoacetophenon . The stability constants and the rate constants of the reactions under optimized conditions and at room temperature were 5*104 L.mole-1, 3.46*10-2 min-1 and 3*106 L.mole -1 , 1.39*10-2 min-1 respectively.