Compósitos de grafite a base poliuretana modificados com SBA-15 na determinação dos antioxidantes BHA e TBHQ em biodiesel

Due to the importance of the antioxidants to guarantee the quality of the biodiesel, by the parameters of its oxidative stability, analytical methodologies have been developed to quantitatively evaluate the antioxidants present in the biodiesel matrices. In this work SBA-15 and Ni- SBA-15 (nickel in...

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Detalles Bibliográficos
Autor: OLIVEIRA, Danielle Cristina Vasconcelos de
Tipo de recurso: tesis de maestría
Estado:Versión publicada
Fecha de publicación:2017
País:Brasil
Institución:Universidade Federal do Maranhão (UFMA)
Repositorio:Biblioteca Digital de Teses e Dissertações da UFMA
Idioma:portugués
OAI Identifier:oai:tede2:tede/1958
Acceso en línea:https://tedebc.ufma.br/jspui/handle/tede/1958
Access Level:acceso abierto
Palabra clave:SBA-15
Eletrodo modificado
Antioxidantes BHA
TBHQ
Modified electrode
Antioxidants BHA
Química Analítica
Descripción
Sumario:Due to the importance of the antioxidants to guarantee the quality of the biodiesel, by the parameters of its oxidative stability, analytical methodologies have been developed to quantitatively evaluate the antioxidants present in the biodiesel matrices. In this work SBA-15 and Ni- SBA-15 (nickel incorporated in the SBA-15) were synthesized by the hydrothermal method and characterized, being used as modifier (2.5%) in polyurethane graphite based electrochemical sensors to compare their Performance in determining the antioxidants BHA (3-tert-butyl-4-hydroxyanisole) and TBHQ (tert-butylhydroquinone). Among the sensors used, the GPU electrode modified with SBA-15 was the one that presented the best response in the determination of the antioxidants in the preliminary tests, being then applied in the determination of the antioxidants in the biodiesel sample, using the technique of Differential Pulse Voltammetry (DPV ), Using BR as buffer pH = 2 as the electrolyte. The proposed method presented a linear response in the antioxidant determinations (0.993, for TBHQ determinations and 0.977 for BHA determinations), good results for the limit of detection (LOD BHA = 1, (2.03 for determinations of TBHQ and 2.13 for determinations of BHA) and accuracy (102.5% for determinations of TBHQ and 98, 97% for BHA determinations).