Determinação de pesticidas e compostos relacionados em água de superfície e efluente industrial empregando extração em fase sólida e cromatografia gasosa acoplada à espectrometria de massas

• Ano de defesa: 2004
• Autor(a) principal: Martins, Manoel Leonardo
• 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: Química; Química analítica; Efluentes industriais; Água; Pesticidas; CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA
• Link de acesso: http://repositorio.ufsm.br/handle/1/10387

To assist the growing nutritious demand, caused by the great population increase, the use of pesticides has been intensified in the agriculture. Such products improve the agricultural productivity and could reduce the food prices. On the other hand, starting from the results of studies of toxicological, carcinogenic and teratogenic effects of the pesticides and of the raw material used in their production, more and more rigid control parameters have been established, in the order of micro- to picogram per liter of water or per kilogram of soil or food. The control of these substances in the water requests fast, cheap and reliable analytical procedures that allow the determination of a great variety of pesticides and related compounds, with varied chemical properties and belonging to different chemical classes. In the present work it has been developed and validated a procedure for quantification of 4-chloro- α,α,α- trifluoro-toluene, o-xylene, m-xylene, p-xylene, 4-chloro-toluene, 3,4-dichloro- α,α,α- trifluoro-toluene, 4-chloro-3-nitro-α,α,α-trifluoro-toluene, 2,2-dichloroethenol-dimetyl-phosphate, trichlorfon, 3,4-dichlorophenyl isocianate, diuron, 4-chloro-3,5-dinitro-α,α,α- trifluoro-toluene, 3,4-dichloroaniline, 1-(4-Chlorophenyl)-4,4-dimethyl-3-pentanone, trifluralin, 2-[2-(4-Chlorophenyl)ethyl]-2-(1,1-dimethyl-ethyl)-oxirane, lindane, propanil, 2,4-D ester (Butyl, 2,4-dichlorophenoxi-acetate), chlorpyrifos, 2-bromomethyl-2-(2,4-dichlorophenyl)-4-propyl-1,3-dioxolane), α-endosulfan and β-endosulfan in treated industrial effluent and surface water samples using the Solid Phase Extraction (SPE), for extraction and pre-concentration, and Gas Chromatography coupled to Mass Spectrometry/Mass Spectrometry (GC-MS/MS) for the quantification. In SPE, cartridges containing a polymer with lipophilic and hydrophilic characteristics have been used, with capacity for extraction of acid and basic compounds (Abselut NEXUS, Varian). The chromatographic separation conditions were: analytical column VF - 5ms of low bleeding (Factor Four, Varian) of 30 m x 0.25 mm; 0.25 mm); carrier gas: helium, flow-rate 1.2 mL min-1; injected volume: 1 μL (splitless); programming of the column oven temperature: 45 °C 1.5 min, 260 °C (10 °C min-1) - 4 min; detector: mass spectrometer, ion trap type operating in the MS/MS way, multisegment; temperatures: transfer line: 290 °C, manifold: 80 °C and ion trap: 240 °C. In the validation of the procedure, the following parameters were appraised: detection limit (LOD), quantification limit (LOQ), linearity, precision (repeatability and intermediate precision) and recovery. The LODs obtained with the procedure were between 0.07 and 0.78 mg L-1 and the LOQs were between 0.21 and 2.44 mg L-1. The precision assays supplied acceptable results with RSD values between 1.3 and 11.9%. The recoveries were from 50.0 to 155.3%. The results obtained in this work allowed the conclusion that the proposed analytic procedure is efficient and precise for the determination of 4-chlorotoluene, 4-chloro-3-nitro-α,α,α-trifluoro-toluene, 2,2-dichloroethenol-dimetylphosphate, trichlorfon, 2-[2-(4-Chlorophenyl)ethyl]-2-(1,1-dimethyl-ethyl)-oxirane, trifluralin, lindane, chlorpyrifos, 2-bromomethyl-2-(2,4-dichlorofenyl)-4-propyl-1,3-dioxolane), α-endosulfan and β-endosulfan in industrial effluent and superficial water samples. For these compounds the precision assays supplied acceptable results with RSD values between 1.3 and 10.4%. The recoveries were from 71.7 to 128.8%. The recoveries obtained for the other compounds indicate the need to optimize the procedure to allow the analysis in the whole strip of concentrations wanted.