Determinação voltamétrica do ácido aminometilfosfônico (AMPA) em amostras de água

• Ano de defesa: 2016
• Autor(a) principal: Silva, Josiely Simões da
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal da Paraíba; Brasil; Química; Programa de Pós-Graduação em Química; UFPB
• Palavras-chave em Português: Química; Ácido aminometilfosfônico; Glifosato; Eletrodo de cobre; Eletrodo de cobalto; Chemistry; Aminomethylphosphonic acid; Glyphosate; Cooper electrode; Cobalt electrode; CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA
• Link de acesso: https://repositorio.ufpb.br/jspui/handle/123456789/11596

The aminomethylphosphonic acid (AMPA) it is the main metabolic product of glyphosate, one of most used herbicide in Brazil and worldwide. A lot of studies shows the toxicity level of glyphosate and, in this way, many countries have laws who determines the maximum quantities allowed in food. However, just a few of them extend their restriction to the metabolite, not considering his toxicological potential. In this work, it was developed voltammetric methods of AMPA’s determination using cooper and cobalt electrodes as work electrode. Initially, the AMPA’s voltammetric behavior on the cooper electrode was studied under phosphate buffer between pH 6,0-9,0 and on cobalt electrode, pH 7,0-10,0, using cyclic voltammetric. The ideal pH was 7,0 for both electrodes considering the highest sensibility on the metal-AMPA complex detection. For the determination with cooper electrode the square wave voltammetric was the chosen technique, while differential pulse voltammetric it was the chosen technique for the determination with cobalt electrode. The parameters of square wave voltammetric and differential pulse voltammetric techniques was evaluated on pH 7,0 to increase the detection sensibility. With the cooper electrode it was found detection and quantification limits of 6.51 nmol L-1 and 21.7 nmol L-1, respectively, and with the cobalt electrode, 11.7 nmol L-1 and 39.1 nmol L-1, respectively. The methods accuracy it was evaluated through apparent recovery on potable water samples fortified with AMPA using the standard addition method, without the change of the support-eletrolyte. The averages recoveries was from 93% to 104% to the cooper electrode, and from 97% to 113% for the cobalt electrode, pointing that both electrodes can be applied to AMPA’s determination in water samples.