Reprint of "Genotoxic permanent hair dye precursors p-aminophenol and p-toluenediamine electrochemical oxidation mechanisms and evaluation in biological fluids"

Author(s)

de Souza, Joao Carlos ; Boldrin Zanoni, Maria Valnice ; Oliveira-Brett, Ana Maria

• Document type: Journal article
• Source: JOURNAL OF ELECTROANALYTICAL CHEMISTRY; v. 872, p. 7-pg., 2020-09-01.

Abstract

The p-toluenediamine (PTD) and p-aminophenol (PAP), genotoxic precursor agents widely used in permanent hair dyeing formulations, electrochemical mechanisms and evaluation in biological fluids, at a glassy carbon electrode, in a wide pH range, by cyclic, differential pulse, and square wave voltammetry, were investigated. The oxidation of both PTD and PAP is reversible. The PTD two electrons and two protons transfer diffusion-controlled reaction occurs at the molecule nitrogen atoms in the amine groups. Also PAP oxidation is a two electrons and two protons transfer diffusion-controlled reactions, and occur at the nitrogen and oxygen atoms of the molecule amine and hydroxyl groups. An electrochemical oxidation mechanism for PTD and PAP is proposed. The PTD and PAP diffusion coefficients, D-PTD = 1.57 x 10(-5) cm(2) s(-1) for PTD, and D-PAP = 1.03 x 10(-5) cm(2) s(-1) for PAP, were determined. The electrochemical quantification in 0.10-1.00 mu M concentration range showed a detection limit of 0.12 mu M for PTD and 0.17 mu M PAP. A new electroanalytical method for the determination of PTD and PAP in fetal bovine serum biological fluid, and in artificial urine samples, using differential pulse voltammetry, was also developed. (AU)

• FAPESP's process: 18/12449-6 - Study of the electrochemical behavior of keratin and its interaction with p-toluenediamine and p-aminophenol and their oxidation products mimicking reactions of permanent hair dye
• Grantee: João Carlos de Souza
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• FAPESP's process: 15/12998-1 - Chromatographic and electroanalytical methods applied in determination of p-toluenediamine and p-aminophenol in oxidative medium used in permanent hair dye.
• Grantee: João Carlos de Souza
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 14/50945-4 - INCT 2014: National Institute for Alternative Technologies of Detection, Toxicological Evaluation and Removal of Micropollutants and Radioactivies
• Grantee: Maria Valnice Boldrin
• Support Opportunities: Research Projects - Thematic Grants