ANáLISE DE RESíDUOS DO INSETICIDA METAMIDOFóS EM SOJA E DETERMINA??O FINAL POR CROMATOGRAFIA EM FASE GASOSA

摘要

Neste trabalho prop?e-se método rápido deprocedimentos de extra??o e clean up paradetermina??es do inseticida Metamidofós emamostras de soja. Análises de amostras de soja secae hidratada, fortificadas em níveis de 5 μg g-1,apresentaram recupera??o média de 93-94% ecoeficiente de varia??o de 17 a 31% com os sistemasadsorvente alumina/florisil e eluente metanol/acetonitrila 1:3. Testes empregando sílica 15%desativada também mostraram eficiência comrecupera??o final de, aproximadamente, 75% ecoeficientes de varia??o entre 18 a 27%.Cromatogramas com mínima interferência, nenhumefeito de matriz e boa eficiência na extra??o foramobtidos com a aplica??o do método proposto. METHAMIDOPHOS INSECTICIDE RESIDUE ANALYSIS IN SOYBEAN AND FINAL DETERMINATION BY GASCHROMATOGRAPHY Abstract A rapid method for extraction and clean up procedures for methamidophos insecticide determinations in soybean samplesis proposed in this work. Analyses of dried and natural soybean samples fortified at 5 μg g-1 level showed recoveriesaverage of 93-94% and variation coefficient ranging from 17 to 31% by using 3:1 Alumina/Florisil adsorbent systemcombined with 1:3 methanol/acetonitrile as eluent system. Tests employing 15% deactivated silica also showed to beefficient with final recovery close to 75% and variation coefficients varying from 18 to 27%. Chromatograms with minimalinterferences, no matrix effects and good extraction efficiencies were recorded after application of the proposedmethod.