SciELO - Scientific Electronic Library Online

 
vol.14 número2LC-MS-MS identification of drug metabolites obtained by metalloporphyrin mediated oxidationDetermination of fluoride in coal using pyrohydrolysis for analyte separation índice de autoresíndice de materiabúsqueda de artículos
Home Pagelista alfabética de revistas  

Journal of the Brazilian Chemical Society

versión impresa ISSN 0103-5053

Resumen

FERREIRA, Edilene C.; SOUZA, Gilberto B.  y  NOGUEIRA, Ana Rita A.. FIA-FAAS method for tannin determination based on a precipitation reaction with hemoglobin. J. Braz. Chem. Soc. [online]. 2003, vol.14, n.2, pp. 329-333. ISSN 0103-5053.  http://dx.doi.org/10.1590/S0103-50532003000200023.

A flow system, coupled with flame atomic absorption spectrometry (FIA-FAAS), was developed for tannin determination in pigeon pea samples, exploring the precipitation reaction between tannins and proteins. Sample extracts obtained by sonication with a 50% (v/v) methanol solution were introduced into the system and induced to react with a hemoglobin solution. The precipitate produced was retained on a filter located in the analytical flow. A reversed flow of 1% (w/v) sodium dodecyl sulfate solution was used for solubilization of the precipitate from the filter and to conduct the tannin-hemoglobin complex to the FAAS, to quantify the iron ions present in the hemoglobin structure. A tannic acid solution was used to prepare the analytical curve. The proposed method allowed determination of 30 samples per hour, a standard deviation of 9.7% (n=10), and a quantification limit of 0.27 mg L-1 for tannic acid.

Palabras llave : tannin-protein complexes; hemoglobin; FIA; flame atomic absorption spectrometry.

        · resumen en Portugués     · texto en Inglés     · pdf en Inglés