Ozonização no tratamento da água para remoção de microcistina-lr e validação do método de análise por lc-ms/ms

• Ano de defesa: 2008
• Autor(a) principal: Machado, Andrea Ferreira
• Orientador(a): Pires, Marçal José Rodrigues
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Pontifícia Universidade Católica do Rio Grande do Sul; Porto Alegre
• Palavras-chave em Português: ENGENHARIA DE MATERIAIS; OZONIZAÇÃO; ÁGUA - TRATAMENTO
• Link de acesso: http://hdl.handle.net/10923/3346

The microcystins (MCs) are toxins from cyanobacteria characterized as hepatotoxins, which present an action of poisoning that can cause death in few hours and few days. Among MCs the microcystin-LR (MC-LR) is known the most toxic and common. The aim this study was to evaluate the decrease of the concentration of MC-LR in samples of water by using ozonation and to optimize and to validate the method for MC-LR determination in water by LC-MS/MS. The linearity was obtained through the calibration curve (0. 05 - 0. 5 mg L-1) with good results, r2> 0. 99. The repeatability and reproducibility were obtained by spike of blank samples in different days and had satisfactory results (CV% <20). The detection limit (LOD) and the quantification limit (LOQ) attended the established by legislation (<1. 0 μg L-1). The analysis using LC-MS/MS in MRM mode (monitoring two fragments), demonstrates the specificity and selectivity of the method, together with the absence of the effect matrix for drinking water and surface water. The results of this work showed ozonation was effective for removing MC-LR at levels greater than those likely to be found in drinking water, and it is able to remove the toxin from water until levels below established by legislation. The treatment with steady concentration of ozone was able to remove 87. 7% of the toxin in 60 minutes of reaction. A solution of MC-LR of 0. 1 mg L-1 needed a dose of 0. 09 mg L-1 of stock solution of ozone for total removal of the toxin, the sample of surface water containing 0. 03 mg L-1 of MC-LR requested a dose of ozone of 6. 00 mg L-1. It was possible to conclude that components present in the matrix, such as organic matter, also reacted with ozone being required higher doses for removal of MC-LR.