Spectrophotometric determination of acetaminophen and salicylamide through nitrosation and subsequent chelation

Abstract

A nitrosation reaction has been adopted for the spectrophotometric determination of acetaminophen and salicylamide. The selectivity of the reaction is increased through utilisation of the nitroso derivatives as chelating agents for cobalt(II) and copper(II) ions. The optimum experimental conditions for the application of nitrosation and nitrosation with subsequent chelation were established. The proportions of reactants in each method and the instability constants for the products were determined. The nitroso derivatives and their chelates obey Beer's law and their absorbances were used for the determination of acetaminophen and salicylamide in pharmaceutical formulations. The proposed methods gave more accurate results than the official methods.