FIA-FAAS method for tannin determination based on a precipitation reaction with hemoglobin

Autor(es)

Edilene C. Ferreira ; Gilberto B. Souza ; Ana Rita A. Nogueira ^[3]

• Tipo de documento: Artigo Científico
• Fonte: Journal of the Brazilian Chemical Society; v. 14, n. 2, p. 329-333, 2003-04-00.

Resumo

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. (AU)

• Processo FAPESP: 98/10814-3 - Preparo de amostras agronômicas e determinações multielementares por espectrometria de emissão atômica em plasma induzido
• Beneficiário: Joaquim de Araújo Nóbrega
• Modalidade de apoio: Auxílio à Pesquisa - Temático