Microanálise em trabalhos de rotina
II - Avaliação de proteínas
Palavras-chave:
processo kjeldahl, erro experimental, análise química, transporte de amoníaco, microdifusão de amônioResumo
Three forms of the Kjeldahl process were compared with one another to determine which would be most suitable for routine work: 'Macroanalysis', in which ammonium was distilled; 'Semi- microanalysis', in which ammonium was transported by vapor; and 'Microanalysis', in which ammonium was transported by dif- fussion (Conway).
During the analyses, using a variety of samples ranging from one to 60% of protein, it was realized that the com- sumption of reagents as well as the size of the sample do not serve to distinguish among the three forms.
The coefficients of variation in a representative series of the analyses were about 6% (Macroanalysis), 2% (Semimicroanalysis) and 1% (Microanalysis). Semimicroanalysis requires much more expensive equipment. Microanalysis requires the longest time, but has the advantage of permiting a fairly high number of repeated analyses of a single sample without requiring much handling.
Referências
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