Indirect spectrophotometric determination of paracetamol via oxidative coupling reaction with 4-(2-pyridylazo)-resorcinoI


A rapid, sensitive and simple spectrophotometric method is proposed for the determination of paracetamol, The method is based on the oxidation of the hydrolytic product of paracetamol by potassium periodate and coupled with 4-(2-pyridylazo)-resorcinoI in the presence of sodium hydroxide. The absorbance of the yellowish-brown product is measured at 450 nm and the molar absorptivity found to be 5252 l.mol" '.cm'1. The product conforms to Beer's law over the range 0.4-22.0fig ml". The method is successfully employed for assay of paracetamol in tablets and results have been compared with those obtained by the official method.Keywords: Paracetamol; oxidative coupling; spectrophotometry.