OXIDATION OF ASCORBATE AND ASCORBIC-ACID AT THE AQUEOUS-VERTICAL-BAR-ORGANIC SOLUTION INTERFACE

An electron transfer reaction between ascorbate in an aqueous solution and oxidizing agents in an organic solution immiscible with water has been studied for the first time by polarography for charge transfer a t the interface between two immiscible electrolyte solutions. PL rever sible electron transfer polarogram at the aqueous/organic solution int erface could be observed when teterachlorobenzoquinone, dibromobenzoqu inone and Meldola's Blue were used as oxidizing agents in the organic solution. The oxidation reaction of ascorbate at the aqueous/organic i nterface was discussed comparing with the reactions at the ordinary el ectrodes and in homogeneous solutions. The half-wave potentials of ele ctron transfer polarograms at the aqueous/nitrobenzene interface were applied to evaluate the formal redox potential of ascorbate/ascorbate free radical.