Rapid determination of lead in progressive hair dye lotion by spot test/diffuse reflectance spectroscopy with a paper platform

• Autor(a) principal: Luiz, Vitor H. M. [UNESP]
• Data de Publicação: 2015
• Outros Autores: Saraiva, Lívia M. [UNESP], Martins, Ângela P. [UNESP], Pezza, Leonardo [UNESP], Pezza, Helena R. [UNESP]
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.5935/0103-5053.20150200; http://hdl.handle.net/11449/177517
• topic: Diffuse reflectance spectroscopy; Lead; Progressive hair dye; Spot test

A simple, inexpensive, and clean methodology employing a combined spot test/diffuse reflectance spectroscopy procedure was developed and applied for the quality control analysis of lead in hair dyes, using a filter paper platform. The method is based on the complexation reaction of lead, present in a pH 2.8 buffer medium containing tartaric acid and sodium and potassium tartrate, with sodium rhodizonate (ROD) in an aqueous medium containing sodium dodecyl sulfate (SDS) surfactant, yielding a colored compound on the surface of a filter paper. The concentrations of ROD and SDS were optimized using experimental design. The linear range obtained for reflectometric measurements carried out at 545 nm was 4.70-140 mg L^-1 of lead (R = 0.998), and the limits of detection and quantification were 1.12 and 3.75 mg L^-1 , respectively. The proposed method was successfully applied to the analysis of lead in progressive hair dyes.