It was found that an iodine-modified platinum electrode gives a linear potentiometric response to 1.0 × 10-5 to 1.0 × 10 -3 M ascorbic acid in model solutions. Ascorbic acid in some preparations was determined by potentiometry. The contribution of ascorbic acid to the total antioxidant capacity of aqueous extracts of hips, hop cones, and lemon juice was estimated
