Spectrophotometric study of 2-aminophenol and catechol via reaction with p-aminoacetophenone

Abstract EN

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.