Title of article :
A critical study of use of the Fe(II)/3-hydroxy-4-nitroso-2,7-naphthalenedisulfonic acid complexes in the quantification of polyphenols in medicinal plants
Author/Authors :
da Silva، نويسنده , , Diego Xavier and de Souza، نويسنده , , Maryane Woth and Corrêa، نويسنده , , Camila dos Santos and Moya، نويسنده , , Horacio Dorigan، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2013
Abstract :
A critical study of the use of the Fe(III)/3-hydroxy-4-nitroso-2,7-naphthalenedisulfonic acid (NRS) complexes on the quantification of the polyphenols content in aqueous extracts of plants, expressed as pyrogallic acid, [PA], is presented. The reaction used is based on the reduction of Fe(III) to Fe(II) by [PA] in the presence of NRS in a buffered medium (Tris; pH 8.0) with formation of Fe(II)/NRS complexes. A calibration curve of absorbance (at 730 nm) vs. [PA] is linear (r = 0.998; n = 7) from 1.0 to 7.0 μmol L−1 [PA]. LD and RSD were 0.5 μmol L−1 and 2.5% (6.0 μmol L−1 [PA], n = 10), respectively. The influence of pH, type of buffer solution and interfering species possibly present in the samples were evaluated. Aqueous extracts of twelve medicinal plants used in the Brazilian folk medicine were analysed by using both Fe(III)/NRS complexes and the Folin–Ciocalteu reagent.
Keywords :
medicinal plants , Polyphenols , 7-naphthalenedisulfonic acid , 3-Hydroxy-4-nitroso-2 , Spectrophotometry
Journal title :
Food Chemistry
Journal title :
Food Chemistry