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

• Published in: South African journal of chemical engineering Vol. 25; no. 1; pp. 48 - 53
• Main Authors: Boumya, W., Laghrib, F., Lahrich, S., Farahi, A., Achak, M., Bakasse, M., El Mhammedi, M.A.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-06-2018; South African Institution of Chemical Engineers (SAIChE); Elsevier
• Subjects: Azo coupling; Chronoamperometry; DNPH; Salicylic acid; DNPH; salicylic acid; Chronoamperometry; Azo coupling
• ISSN: 1026-9185
• DOI: 10.1016/j.sajce.2018.01.002

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.
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•CA method was used for SA detection based on coupling reaction with DNPH oxidized.•The mechanism of interaction between SA and DNPH oxidized was investigated.•All parameters affecting the azo coupling reaction have been optimized.•The present method has been applied to detect SA in pharmaceutical samples.