Estudo comparativo de processos de mineralizacao e de metodos de analise de potassio em folhas de tabaco flue-cured.
1990
Rebelo M.C. | Campos L.S.
PORTUGUES: Propomo-nos comparar os teores de potassio determinados por espectrofotometria de absorcao atomica, hoje a tecnica mais avancada de determinacao mineral em material vegetal, com os obtidos por fotometria de chama em folhas de tabaco flue-cured. Comparamos dois processos de obtencao do extracto da amostra, tendo sido feita a mineralizacao por via humida e por via seca nas mesmas amostras, cujas folhas foram separadas em nervura e parenquima. Concluimos que na digestao por via humida o acido perclorico se mostrou interferente mas, quando completamente eliminado, o processo de digestao e indiferente e tambem e indeferente usar qualquer das tecnicas analiticas ensaiadas para a determinacao de potassio.
Show more [+] Less [-]English. Potassium determinations in plant material by atomic absorption spectrophotometry may present difficulties in the less developed countries of the tropics, on account of the expensive equipment required. So, results of determinations of this element made by this method was compared with that obtained by flame photometry to evaluate his relative merit. Both the lamina and mibrid of flue-cured tobacco leaves were analysed after being reduced to ashes by wet and dry procedures. It is concluded that dry or wet preparation of the ashes and the analytical methods are equivalent as long as precautions are taken with the portion of perchloric acid used in the wet preparation.
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