Rapid Potentiometric Determination of Ascorbic Acid Using Iodate as a Reagent

What is proposed in is proposed a fast and simple kinetic potentiometric method for the determination of ascorbic acid (AA) in pharmaceuticals. The method was based on the reaction between AA and iodate to form iodide. A combined iodide ion-selective electrode was used in order to monitor the change in iodide concentration. In the process of a univariate optimization study, experimental conditions were determined that allow a linearity between the concentration and the change of potentials, Delta E, in the range from 8.0.10(-5) to 8.0.10(-4) mol L-1. Less than two minutes' time was needed for the proposed method to enable determination of the AA in pharmaceuticals with satisfactory recovery and the usual excipients did not act as interference.