Estudo comparativo de métodos de extração multirresíduo de agrotóxicos em maçã e tomate

• Autor(a) principal: Mansur, Bethânia Leite
• Data de Publicação: 2013
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2165
• topic: QuEChERS; ESL/PBT; Cromatografia gasosa; Extração multirresíduo; QuEChERS; ESL / PBT; Gas chromatography; Multiresidue extraction; CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA::QUIMICA ANALITICA

This study aimed to compare two multiresidue extraction methods: the solid-liquid extraction with low temperature partitioning (SLE/LTP) and the extraction QuEChERS (Quick Easy Cheap Effective Ruggedand Safe Method) of the chlorpiryfos, deltamethrin and thiamethoxan in apple, and cypermethrin, λ-cyalothrin, chlorpiryfos and deltamethrin in tomato, as well as analysis by Gas Chromatography with Electron Capture Detector (GC/ECD). The results showed that the linearity of the detector response showed to be satisfactory for all compounds. In relation to the chromatographic aspects, QuEChERS reduced baseline shift. In the validation of methodologies, the SLE/LTP extraction had lower limit of detection (LOD of 10 to 13 μg kg-1) and quantification (LOQ of 30 to 39 μg kg-1). As for linearity, both were acepptable. Regarding accuracy, both showed good accuracy but with less accuracy in the extraction of deltamethrin in tomatoes at low concentrations. In repeatability, the two methodos presented coefficient of variation (CV) below the maximum allowed of 15%. In terms of intermediate precision in the tomato, both techniques decreased in lower concentrations of analytes. In apple, the intermediate precision varied less as a function of the change in the concentration of the analyte by the QuEChERS method. On the matrix effect, the SLE/LTP is more in both matrixes. However, with increasing time fortification in QuEChERS methodology, its matrix effect is almost equal to or larger than the SLE/LTP. The modification of the SLE/LTP extraction tried to reduce the number of steps in the analytical procedure. The option to perform the method QuEChERS original aims to show that with fewer steps in the procedure, and other factors, similar results can be obtained using the SLE/LTP making it more feasible to be implemented, for example, a large number of samples.