High-performance liquid chromatographic method to evaluate the hydrogen atom transfer during reaction between 1,1-diphenyl-2-picryl-hydrazyl radical and antioxidants

Abstract : 1,1-Diphenyl-2-picrylhydrazyl (DPPH·) is a stable nitrogen centred radical widely used to evaluate direct radical scavenging properties of various synthetic or natural antioxidants (AOs). The bleaching rate of DPPH· absorbance at 515nm is usually monitored for this purpose. In order to avoid the interference of complex coloured natural products used as antioxidant supplements or cosmetics, HPLC systems have been reported as alternative techniques to spectrophotometry. They also rely upon measurement of DPPH· quenching rate and none of them permits to identify and measure 1,1-diphenyl-2-picryl-hydrazine (DPPH-H), the reduced product of DPPH· resulting from hydrogen atom transfer (HAT), which is the main mechanism of the reaction between DPPH· and AOs. We presently report an HPLC method devoted to the simultaneous measurement of DPPH· and DPPH-H. Both were fully separated on a C18 column eluted with acetonitrile-10 mM ammonium citrate buffer pH 6.8 (70:30, v/v) and detected at 330 nm. Adsorption process of DPPH· onto materials of the HPLC system was pointed out. Consequently, the linearity range observed for DPPH· was restricted, thus a much lower limit of detection was obtained for DPPH-H than for DPPH· using standards (0.02 and 14 μM, respectively). The method was applied to three commonly used AOs, i.e. Trolox(®), ascorbic acid and GSH, and compared with spectrophotometry. Further application to complex matrices (cell culture media, vegetal extracts) and nanomaterials demonstrated (i) its usefulness because of higher selectivity than colorimetry, and (ii) its help to investigate the mechanisms occurring with the free radical.
Type de document :
Article dans une revue
Analytica Chimica Acta, Elsevier Masson, 2012, 711, pp.97 - 106. 〈10.1016/j.aca.2011.10.063〉
Domaine :
Liste complète des métadonnées

https://hal.univ-lorraine.fr/hal-01491844
Contributeur : Cithefor Ul <>
Soumis le : vendredi 17 mars 2017 - 14:33:57
Dernière modification le : mercredi 17 janvier 2018 - 09:02:06

Identifiants

Collections

Citation

Ariane Boudier, Juliana Tournebize, Grzegorz Bartosz, Safae El Hani, Rachid Bengueddour, et al.. High-performance liquid chromatographic method to evaluate the hydrogen atom transfer during reaction between 1,1-diphenyl-2-picryl-hydrazyl radical and antioxidants. Analytica Chimica Acta, Elsevier Masson, 2012, 711, pp.97 - 106. 〈10.1016/j.aca.2011.10.063〉. 〈hal-01491844〉

Partager

Métriques

Consultations de la notice

28