Avaliação da contaminação de tomate hidropônico com agrotóxicos por cromatografia líquida de alta eficiência

• Ano de defesa: 2012
• Autor(a) principal: Monteiro, Carolina Faria
• Orientador(a): Neves, Antônio Augusto
• Banca de defesa: Zambolim, Laércio , Ambrozim, Alessandra Regina Pepe
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Agroquímica
• Departamento: Agroquímica analítica; Agroquímica inorgânica e Físico-química; Agroquímica orgânica
• País: BR
• Palavras-chave em Português: Agrotóxicos; Tomate; HPLC
• Palavras-chave em Inglês: Pesticides; Tomato; HPLC
• Área do conhecimento CNPq: CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA::QUIMICA ANALITICA
• Link de acesso: http://locus.ufv.br/handle/123456789/2141

In hydroponic culture the occurrence of diseases and pests happens to a lesser proportion when compared to conventional tillage. Even though the incidence of pests and diseases is lower, it is not ruled out the use of pesticides in this culture. For this reason, studies involving the evaluation of contamination in a hydroponic culture are relevant. In this project, a culture of hydroponic tomato located in Viçosa-MG was used to assess contamination by pesticides such determination was carried out using high performance liquid chromatography coupled with UV-Vis detector (HPLC-UVVis) and atomic absorption spectrophotometry. The pesticides used in this culture were: Vertimec 18EC®, Belt® and Supera®, which have the active ingredients abamectin, flubendiamide and copper hydroxide, respectively. For extraction of pesticides flubendiamide and abamectin, from the tomato samples, the method of solid-liquid extraction with low temperature partitioning (SLE-LTP) was used. This method was adapted from a previously performed optimization. Hence a validation was performed covering the following analytical performance parameters: selectivity and matrix effect, response linearity of the method, detection limit, quantification limit, accuracy/recovery and precision (repeatability and intermediate precision). The results showed that the method SLE-LTP and analysis by HPLC-UV-Vis are efficient for the extraction and analysis of pesticides of interest. However, the detection limits presented in the order of 0,56 and 0,72 mg/kg for flubendiamide and abamectin, respectively, are considered high when compared with MRL (maximum limit of residues) of active ingredients. For flubendiamide is 0,10 mg/kg and abamectin is 0,01 mg/kg. The validated method was used to monitor the contamination levels of hydroponic tomatoes from November 2011 to June 2012. During the monitoring period was not detected the presence of these pesticides in the samples. In the evaluation of copper (II), the same samples were subjected to dried digestion, in which the ashes obtained were diluted in HNO3 1 mol/L. The resulting solution was analyzed in a atomic absorption spectrophotometry with flame. The concentrations of copper (II) were between 0,45 and 1,71 mg/kg of the fruit. Such concentrations are below the maximum allowed limit, which is 10 mg/kg. Thus, it can be said that the hydroponic tomatoes are free from contamination, as in levels of detection limits achieved in the validation of the method as the content of cooper (II) found.