Direct and simultaneous quantification of rutin and quercetin in natural fruits base on purified Arabic Gum modified carbon paste electrode

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Résumé

Arabic gum was purified and used as modifier of carbon paste electrode (PAG-CPE) for the simultaneous determination
of quercetin (QT) and rutin (RT) in 0.1 M phosphate buffer solution, pH 6.0. Fourier transform infrared spectroscopy was
used for the identification of different chemical functional groups present at the surface of the raw and the purified arabic
gum. The electrochemical behaviour of QT and RT on the modified electrode was studied using cyclic voltammetry (CV)
and square wave voltammetry. The sensitivities of PAG-CPE for both QT and RT were respectively 2.8 and 3.3-fold greater
than signals obtained on the unmodified CPE in CV. The linear dynamic range for both flavonoids was found within the
concentration range of 0.099–1.090 μmol/L with a detection limit of 0.029 μM and 0.058 μM respectively for QT and RT
(3S/m). The proposed approach was successfully applied, first for the direct quantification of QT and RT in crude natural
fruits and secondly, for the simultaneous detection of both flavonoids in human urine.

Mots-clés

rutin, quercetin, gum arabic, carbon paste electrode, modified electrode, flavonoid determination, urine analysis, electrochemical sensor