Quantitative anodic generation of cerium(IV) in acetic acid

Conditions for the electrochemical generation of cerium(IV) in acetic acid with high current efficiency are described. Coulometric titrations for determining hydroquinone, 2-methylhydroquinone, 2-chlorohydroquinone and ascorbic acid biamperometric or potentiometric end-points are reported; benzidine is viable for visual end-points. Current efficiency depends on the composition and concentration of the supporting electrolyte and the amount of water and acetic anhydride in the anolyte. The formal redox potential of the Ce(IV)/Ce(III) system decreases as concentration of potassium acetate in the solution increases.