Avaliação de material alternativo para uso como adsorvente na extração em fase sólida de resíduos de pesticidas em estipe de coqueiro (Cocos nucifera L)

• Ano de defesa: 2014
• Autor(a) principal: Jesus, Jemmyson Romário de
• Orientador(a): Navickiene, Sandro
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Programa de Pós-Graduação: Pós-Graduação em Química
• Palavras-chave em Português: Química analítica; Análise cromatográfica; Pesticidas; Coqueiro; Cocos nucifera L.; Polímeros de coordenação; DMFS; CL-DAD
• Palavras-chave em Inglês: Analytical chemistry; Chromatographic analysis; Coconut palm; Pesticides; Coordination polymers
• Área do conhecimento CNPq: CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA
• Link de acesso: https://ri.ufs.br/handle/riufs/6095

The coconut (Cocos nucifera L) is a rich source of nutrient and as well as other plants is under attack from different types of pests and diseases, causing losses to producers. Pesticide use remains the primary control strategy and combat pests and diseases in agricultural crops. However, the excessive and indiscriminate use of these products can cause serious harm to human health and the environment due to the high toxicity these products. In Brazil, until now no stipulated values of maximum residue limits (MRLs) for pesticides in coconut crops. Similarly, there is little information about the degree of contamination. Therefore analytical methodologies must be developed for the determination of pesticide residues in coconut cultivation, aiming to ensure human health. Thus, this work proposes a methodology to determine residue of bromopropylate, clofentezine, coumaphos, difenoxuron, diniconazole, fenvalerate, flumetralin, flumeturon, teflubenzuron in greens stipe, appling the matrix solid phase dispersion (MSPD) and liquid chromatography with diode array detector (LC-DAD) for analysis. In this study we evaluated the best sorbent/solvent combinations (using silica, Florisil, neutral alumina, C18 and coordination polymers [Zn(BDC)(H2O)2]n, [Zn(BDC)0.99(NH2-BDC)0.01)(H2O)2]n, [Zn(BDC)0.95(NH2-BDC)0.05)(H2O)2]n, [Zn(BDC)0.90(NH2-BDC)0.10)(H2O)2]n/acetonitrile), the best ratio of sample/ adsorbent mass, as volume of the elution solvent used for extraction were evaluated. Among the investigated combinations, the system comprising 0.25 g of stem, 1 g of neutral alumina and 5 mL of acetonitrile was the most efficient in recovery resulting from 70 and 93%, with relative standard between 1.6% and 10%, in the levels of concentration 0.04, 0.08, 0.2, 0.4, 2.0, 3.0; 4.0 ìg g-1. The linearity was above 0.9991 and the limits of detection between 0.01 and 0.05 ìg g-1 and quantification 0.05 and 0.2 ìg g-1. Among the polymeric phases, the [Zn(NH2BDC)0.1(BDC)0.9(H2O)2]n was most eficiente in the extraction of bromopropylate, clofentezine, coumaphos, difenoxuron, diniconazole, fenvalerate, flumetralin, flumeturon and teflubenzuron.