Figure 8. 1-HP-iron complex is a quasi-irreversible redox system.

(A) Cyclic voltammetry at 100 mV/s on a gold disc electrode with 1 mM of PYO (red), 1 mM of FeCl₃ (green) and a mixture of PYO-FeCl₃ in the ratio (1:0.1) in violet, (1:0.5) in blue and (1:1.5) in orange. (B) Cyclic voltammetry at 100 mV/s on gold disc electrode with 1 mM of 1-HP (red), 1 mM of FeCl₃ (green) and a mixture of 1HP-FeCl₃ (1:1) (blue). The arrow indicates the direction from initial potential.