Spectrophotometric analysis of the iron chelation stoichiometry of DFX and CPX.

(A) Spectra of DFX and CPX solutions in water (100 μmol/L) with or without 100-μmol/L ferrous ethylenediammonium sulfate. (B) Relationship between iron:chelator molar ratio and relative absorption at 430:226 nm19 and 421:247 nm for DFX and CPX, respectively. The chelator concentrations were held constant at 100 μmol/L in the presence of the indicated molar ratios of ferrous ethylenediammonium sulfate.