VOLTAMMETRIC DETERMINATION OF FOLIC ACID WITH A OVEROXIDIZED POLYPYRROLE FILM MODIFIED SOL-GEL CARBON CERAMIC ELECTRODE

The electrochemical behavior of folic acid (FA) was studied at an overoxidized polypyrrole modified carbon ceramic electrode using cyclic voltammetry. The numerous factors affecting the oxidation peak currents of folic acid on the response of the electrode were optimized to maximize sensitivity. The modified electrode presented a linear response range for FA concentration from 7 to 55 mu M, 0.1 to 25 mu M, and from 0.49 to 7.8 mu M with detection limits of 1.8 x 10(-6), 3.1 x 10(-8), and 2.7 x 10(-7) for cyclic voltammetry, differential pulse voltammetry, and amperometric techniques, respectively. The results showed that the OPPy-modified electrode has very high catalytic ability for electrooxidation of FA. The modified electrode exhibited excellent sensitivity and stability. The application of the modified electrode was demonstrated for determination of folic acid in biological and other real samples.