Kinetic Study of Paracetamol Hydrolysis: Evaluating of the Voltammetric Data

Hydrolysis of paracetamol in acidic media was studied using electrochemical technique in different reaction temperatures. Based on the fact that both paracetamol (PAR) and its hydrolyzed product, p-aminophenol (PAP) are both electroactive and their voltammetric peaks do not overlap, differential pulse voltammetry was used for the determination of the remained PAR concentration in the reaction vessel as well as produced PAP concentration. Then, the kinetic parameters of PAR hydrolysis including reaction rates and half-lives in various temperatures and the activation energy of the reaction were calculated using proposed accurate method. PAR is hydrolyzed to PAP in the presence of hydronium ion via first-order kinetic reaction with the reaction rates of 8.9×10 -4 , 2.16×10 -3 , 4.21×10 -3 , 6.26×10 -3 and 1.46×10 -2 min -1 at the reaction temperatures of 50, 60, 70, 80 and 90 ̊C, respectively. The activation energy of the hydrolysis reaction was calculated to be 63.61 kJ mol -1 . KeywordsParacetamol, p-Aminophenol, Kinetic study, Voltammetry Analytical & Bioanalytical Electrochemistry © 2014 by CEE www.abechem.com Anal. Bioanal. Electrochem., Vol. 6, No. 4, 2014, 450-460 451