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

Journal of the Brazilian Chemical Society

Universidade Federal de São Carlos, São Carlos, Brazil¹  Ferreira, Edilene C.¹  Nogueira, Ana Rita A.¹  Universidade de São Paulo, São Carlos, Brazil¹  Souza, Gilberto B.¹  Embrapa Pecuária Sudeste, São Carlos, Brazil¹ 

关键词: tannin-protein complexes;    hemoglobin;    FIA;    flame atomic absorption spectrometry;   

DOI  :  10.1590/S0103-50532003000200023

学科分类：化学（综合）

来源: SciELO

【 摘 要 】

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.

【 授权许可】

Unknown