NOTA
Determinação de silício em material vegetal, pelo método colorimétrico do "azul-de-molibdênio"1
Determination of silicon in plants by the molybdenum-blue colorimetric method
Pedro Roberto Furlani2; José Romano Gallo2
SUMMARY
Some aspects of the molybdenum-blue method of silicon determination in plants were studied. It was verified that the formation of the beta-isomer of the silicomolibdic acid, whose molar absorptivity is higher, depends on the solution acidity and the amount of reagent added. This isomer was obtained by adding 5 meq of H2SO4 and 2 ml of a 5% ammonium molibdate solution in a 50 ml calibrated flask. After reduction, the molibdenumblue formed was stabilized by adding 15 meq of H2S04 more. The procedure also involves adding 1 ml of 10% oxalic acid solution, in order to eliminate phosphorus interference. The silicon solubilization, from 100 mg of dry material, was obtained by melting the ashes in nickel dishes with sodium hidroxide. This procedure proved suitable and accurate in the analysis of silicon in plants.
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Recebido para publicação em 7 de maio de 1977.
Datas de Publicação
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Publicação nesta coleção
21 Dez 2007 -
Data do Fascículo
1978