Desenvolvimento de metodologia analítica ambientalmente mais amigável para a determinação de ureía em matrizes diversas

Detalhes bibliográficos
Ano de defesa: 2014
Autor(a) principal: Toledo, Paulo Roberto Aparecido Bueno de [UNESP]
Orientador(a): Não Informado pela instituição
Banca de defesa: Não Informado pela instituição
Tipo de documento: Dissertação
Tipo de acesso: Acesso aberto
Idioma: por
Instituição de defesa: Universidade Estadual Paulista (Unesp)
Programa de Pós-Graduação: Não Informado pela instituição
Departamento: Não Informado pela instituição
País: Não Informado pela instituição
Palavras-chave em Português:
Link de acesso: http://hdl.handle.net/11449/110844
Resumo: Green Chemistry principles have guided the development of new analytical procedures aimed at reducing the use of toxic substances and waste production that do not require costly treatment and trained professional13. Based on these principles, this paper proposes the development of a more environmentally friendly method that can be applied to the analysis of urea in milk and cosmetics. Urea is used in numerous industrial sectors for various functional uses as adhesives, binders, sealants, resins, fillers, catalysts, humectants and dehydrating agents. It is also used in supplements for animals, fertilizers and analytical reagents. In consumable products, urea is found in a wide variety of commercial samples such as cosmetics, moisturizers, shampoos, hair conditioners, hair dyes and dye removers, liquid soaps, detergents and other cleaning products, besides being extensively used in treatments for dry skin. In food products, such as cow milk, urea is present in the medium concentration of 160 mg.L-1, but the fraudulent addition of urea in milk to increase profits alters the quality of the milk on all components, especially the milk protein. This tampering directly influences milk payment for their quality. The clean method developed involves combining spot test - diffuse reflectance spectroscopy using two different chromogenic reagents (p-DAB and p-DAC), and was applied for determination of urea in dermatologic formulations and bovine milk, demonstrating great precision and accuracy results, evidenced by good recovery, plus offering advantages such as simplicity of implementation and low reagent consumption, generating minimal amount of waste, speed and security, portability and generating reliable results.