Especiação de cromo em cimentos e derivados de cimento brasileiros
AUTOR(ES)
Matos, Wladiana Oliveira, Nóbrega, Joaquim Araújo
FONTE
Química Nova
DATA DE PUBLICAÇÃO
2009
RESUMO
A method for determination of Cr(III) and Cr(VI) in cement and cement-related materials was studied. Molecular absorption spectrophotometry based on 1,5-diphenylcarbazide as chromogenic reagent was used for determination of Cr(VI) after alkaline extraction. The total chromium concentration was determined using flame atomic absorption spectrometry (FAAS) after complete sample decomposition by fusion. The quantification of Cr(III) was accomplished by subtracting the Cr(VI) concentration from the total chromium concentration. The concentration of Cr(III) in the samples ranged from 10.9 to 88.0 mg kg-1, whereas only in few samples the Cr(VI) concentration was higher than the value established by the European Community to this type of sample [2 mg kg-1 Cr(VI)].
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