Direct Voltammetric Determination of Ascorbic Acid in Natural Paprika Fruits Without Sample Pretreatment

Direct electrochemical measuring technique for estimation of the ascorbic acid (AA) content of freshly cut yellow pepper fruits without special sample treatment was worked out. Dialysis membrane modified glassy carbon electrode combined with short time chronoamperometric measuring method was employed to eliminate the interfering effect of tortuosity and electrode fouling. Viscosity change inside the diffusion layer was taken in account. AA content of the fruit was found to be 114.5 mg/100 g, and it is shown that the metal ions derived from iron blade are able to accelerate the oxidation process significantly. Classical iodometric titration was applied as a reference method.