Electrochemical behavior study of salicylic acid following azo dye formation with 2,4-dinitrophenylhydrazine: Analytical evaluation

• Main Authors: W. Boumya, F. Laghrib, S. Lahrich, A. Farahi, M. Achak, M. Bakasse, M.A. El Mhammedi
• Format: Article
• Language: English
• Published: Elsevier 2018-06-01
• Series: South African Journal of Chemical Engineering
• Online Access: http://www.sciencedirect.com/science/article/pii/S1026918517300811

A new simple, accurate and cost-effective chronoamperometry (CA) - based approach coupled with azo coupling reaction has been put forward for quantitative analysis of salicylic acid. The reaction involves a two-step process of oxidation of the 2,4-dinitrophenylhydrazine (DNPH) by potassium iodate to give a 2,4-dinitrophenylhydrazinium cation at 0–5 °C and coupling with salicylic acid (SA) to form red salicylic acid-derived azo dye. Electrochemical impedance spectroscopy, square wave voltammetry and chronoamperometry methods were used to characterize the electrochemical behavior of the salicylic acid-derived azo dye. Studies on different variables affecting the reaction were optimized. Under the optimal conditions, amperometric studies showed that the current response exhibits a wide linearity range from 0.1 to 0.0005 mmol L−1 for SA and the limit of detection and quantification are found to be 0.0001 and 0.0015 mmol L−1 (S/N = 3 & 10) respectively. Therefore, the developed method was successfully applied for routine determination of SA in pharmaceutical samples. Keywords: salicylic acid, Azo coupling, DNPH, Chronoamperometry