DETERMINAÇÃO DE RESÍDUOS DE AGROTÓXICOS ORGANOCLORADOS EM LARANJA POR DISPERSÃO DE MATRIZ EM FASE SÓLIDA (MSPD) DISSERTAÇÃO DE MESTRADO ECOLOGIA E PRODUÇÃO SUSTENTÁVEL

Abstract

This work shows the results achieved for the evaluation of organochlorine pesticides residue presence in oranges consumed in Goiânia. The method employed was based on the Matrix Solid Phase Dispersion extraction, MSPD, and analyzed by high resolution gas chromatography, GC. The studied pesticides were hexachlorobenzene, atrazine, heptachlor and its epoxide, endrin, a-chlordane and g-clordane. The sample (pulp without seeds) was triturated and 0,5g otit was homogenized in 0,5g of octadecyli silane (C-18). The mixture was transferred to a polyethylene column, containing 1,0g of silica gel 60 activated by 4 hours at 120°C. Three elution solvents were tested: hexane, toluene and ethyl acetate. The recovering percentages of each one were calculated, ranging from 70% to 120%. Considering the blank sample contamination levels from 2 to 5 mg.kg-1. After the analytical parameters determination, the method was tested in commercial sample of Pêra Rio orange, and are endrin residue was found in two of the three studied samples. Those results estimated to be due to the high soil organochlorine persistence or even in the irrigation water used by those farms, since the organochlorine was prohibited in Brazil sinee he 80 s. Key