SIMULTANEOUS SQUARE-WAVE VOLTAMMETRIC DETERMINATION OF RIBOFLAVIN ANDFOLIC-ACID IN PHARMACEUTICAL PREPARATIONS

The square-wave voltammetric (SWV) behaviour of riboflavin and folic a cid was studied at a static mercury drop electrode by square wave volt ammetry. In 0.05 M KCl (pH 5.89) a cathodic scan gave peaks at -0.56 a nd -0.87 V vs. Ag/AgCl for riboflavin and folic acid, respectively. Th e reduction peak currents are linearly dependent on the concentration of vitamins. Both vitamins can be simultaneously determined from the s ame voltammogram. The method proposed for the determination of ribofla vin and folic acid in multivitamin tablets is very simple, rapid and d oes not involve time-consuming separation steps. The average contents of riboflavin and folic acid were found to be 14.8 +/- 1.26% and 1.46 +/- 2.66%, for tablet A and 9.86 +/- 1.40% and 1.47 +/- 2.0% for table t B, respectively.