Potentiometric and spectrophotometric determination of the stability constants of quercetin (3,3 ',4 ',5,7-pentahydroxyflavone) complexes with aluminium(III) and iron(II)


Erdogan G., Karadag R., Dolen E.

REVIEWS IN ANALYTICAL CHEMISTRY, cilt.24, sa.4, ss.247-261, 2005 (SCI İndekslerine Giren Dergi) identifier

  • Cilt numarası: 24 Konu: 4
  • Basım Tarihi: 2005
  • Dergi Adı: REVIEWS IN ANALYTICAL CHEMISTRY
  • Sayfa Sayıları: ss.247-261

Özet

In this study, the stability constants of the complexes of quercetin formed with aluminium(III) and iron(II) were determined potentiometrically by using the Calvin-Bjerrum and Irving Rossotti methods and spectrophotometrically. The evaluated protonation constants of the ligand were found: log K-1=9.63 +/- 0.11 and log K-2=8.32 +/- 013, at 25 degrees C. For the aluminium and iron complexes logarithms of the stability constants were found: for Al: log K-1=14.05 +/- 0.09, log K-2=10.02 +/- 0.12, and for Iron: log K-1=9.44 +/- 0.11, log K-2=3.86 +/- 0.08.