TABLE 3.

Redox potentials for Fe(III) aqueous complex species^a

Reaction	Log K (I = 0)b	E0 (V)	E (V)
Overall redox reactions
Fe(III)-(citrate2)3− + e− → Fe(II)-citrate− + citrate3−	−0.23	−0.014	0.212
Fe(III)OH-NTA− + e− + H+ → Fe(II)-NTA + H2O	9.93	0.587	0.174
Fe(III)-EDTA− + e− → Fe(II)-EDTA2−	0.35	0.080	0.080
Electron transfer reactions
Fe(III)-(citrate2)3− + e− → Fe(II)-(citrate2)4−	1.68	0.099	0.099
Fe(III)OH-NTA− + e− → Fe(II)OH-NTA2−	0.82	0.049	0.049
Fe(III)-EDTA− + e− → Fe(II)-EDTA2−	1.35	0.080	0.080

^aThe standard redox potential (E₀) was calculated from log K, and E is the redox potential under experimental condition.

^bI, ionic strength of the solution.