Spectrophotometric Determination of p-Aminophenol Via Oxidative Coupling Reaction with N-(1-Naphthyl) ethylendiamine dihydrochloride in Presence of Potassium Iodate– Application to Paracetamol

Abstract

Abstract A simple, rapid and sensitive spectrophotometric method for the determination of p-aminophenol is described. The method based on the oxidative coupling reaction of p-aminophenol with N-(1-naphthyl) ethylendiamine (N-NED) using potassium iodate as oxidizing agent in alkaline medium to form a water soluble product, that is stable and has a maximum absorption at 520 nm. Beer’s law is obeyed in a concentration range 10 to 160 µg p-aminophenol / 25 ml with a molar absorptivity of 0.6002×104 L.mol-1.cm-1, a relative error of –0.59 to +4.92% and a relative standard deviation of ± 0.89 to ± 4.49% depending on the concentration of p-aminophenol. The proposed method has been successfully applied to the determination of paracetamol in various pharmaceutical preparations after acidic hydrolysis to p-aminophenol.