Stability constants for complexes of the siderophore desferrioxamine B with selected heavy metal cations

Potentiometric titrations of desferrioxamine B were performed in the presence of Zn(II), Cu(II), Pb(II), Sn(II), Bi(III) and hg(II). Conditions were 0.1 ionic strength and 25 or 20 °C using KNO3, KCl or NaClO4 as supporting electrolyte. Stability constants for the metal complexes were estimated as follows; DFB-Zn(II): 9.55 in KNO3 at 25 °C, DFB-Pb(II): 10.00 in KNO3 at 25 °C, DFB-Sn(II): 21.14 in KCl at 25 °C, DFB-Cu(II): 13.73 in NaClO4 at 20 °C and 13.54 at 25 °C, DFB-Bi(III): > ∼ 23.5 in NaClO4 at 25 °C.