Determinação multirresíduo de agrotóxicos em água empregando microextração líquido-líquido dispersiva (DLLME) e GC-MS/MS

• Ano de defesa: 2015
• Autor(a) principal: Floss, Vagner Medeiros
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Santa Maria; BR; Química; UFSM; Programa de Pós-Graduação em Química
• Palavras-chave em Português: Água; Agrotóxicos; DLLME; GC-MS/MS; Water; Pesticides; CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA
• Link de acesso: http://repositorio.ufsm.br/handle/1/10609

The use of pesticides is related to effectiveness in pest control, as well as productivity in food production in agriculture. However, the use of these substances in high amounts is directly affecting water resources, essential for the maintenance of human life. In Brazil, the Ministry of Health through Ordinance 2914, as well as the Secretariat of the Rio Grande do Sul State Health, by Ordinance 320, stipulate maximum permissible values (VMPs) for pesticides in water. Thus, rapid, sensitive, efficient and generate small amounts of toxic waste analytical methods should be developed to determine the presence and concentration of pesticides and other chemicals in water in order to ensure they are in accordance with current legislation. This study aimed to optimize and validate an analytical method aiming at the extraction and determination of residues of 32 pesticides in water samples by applying the DLLME technical and quantification by gas chromatography coupled to Mass Spectrometry in Triple Quadrupole series (GC-MS / MS). We evaluated the different extractor solvents and dispersor, different volumes of solvents, addition salts, pH variation and time of agitation. The results were satisfactory, with recovery values between 71 and 113% for the tested levels. The coefficients of determination for the curves drawn in the matrix, presented values between 0.9900 to 0.9996. Precision data for the methodology were satisfactory, with values between 1 and 13%. The intermediate precision was RSD values in the range of 5 to 15%, with recoveries in the range 70 to 101% for the level of 0.25 ug L-1. The method presented quantification limit of 0.1 ug L-1 providing the determination of water in pesticide residues with high reliability and security. After validation of this methodology, it was applied to real water samples, in order to evaluate the method developed.