Polarographic Behavior and Determination of Vitamin B13 in Aqueous Media at Dropping Mercury Electrode

The electrochemical reduction of Vitamin B13 (orotic acid)at the dropping mercury electrode (DME) has been investigated. The polarographic behavior of orotic acid in Britton-Robinson (BR) buffersolutions (pH 2-12), in unbuffered solution, in acidic, and also inalkaline solution was measured. The study showed that, the effect of Hg-height on the limiting current and the effect of pH on each of thelimiting current and the half-wave potential of the waves are diffusioncontrolled. The data also showed that under the optimum experimentalconditions, a linear calibration graph was obtained on plotting the concentration of orotic acid versus the height of the reductionwave. A detailed mechanism for the reduction of orotic acid at the dropping mercury electrode correlating the nature of the orotic acid species and its reduction in different media, is proposed.