[Comparative test of mineralisation processes and methods for analysing magnesium in flue-cured tobacco leaves]
1990
Rebelo, M.C. (Ministerio do Planeamento e da Administracao do Territorio, Lisbon (Portugal). Instituto de Investigacao Cientifica Tropical. Centro de Estudos de Producao e Tecnologia Agricolas) | Campos, L.S. (Tecnica de Lisboa Univ. (Portugal). Instituto Superior de Agronomia)
英语. Magnesium 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 colorimetry with Titan yellow 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 method are equivalent if it is used the same salt to prepare the standards for both methods
显示更多 [+] 显示较少 [-]葡萄牙语. A tecnica mais avancada, hoje, para a determinacao de Mg em material vegetal e a espectrofotometria de absorcao atomica. Propomo-nos comparar os teores deste constituinte determinado por esta tecnica com os obtidos por colorimetria com amarelo de tiazol 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 foi indiferente a preparacao do extracto por via humida e por via seca e bem assim a tecnica analitica usada desde que os padroes sejam preparados a partir de solucoes stock do mesmo composto de magnesio
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