Journal of the Brazilian Chemical Society
versión impresa ISSN 0103-5053
TEIXEIRA, Marcos F. S. et al. Determination of vitamin B6 (pyridoxine) in pharmaceutical preparations by cyclic voltammetry at a copper(II) hexacyanoferrate(III) modified carbon paste electrode. J. Braz. Chem. Soc. [online]. 2003, vol.14, n.2, pp. 316-321. ISSN 0103-5053. http://dx.doi.org/10.1590/S0103-50532003000200021.
A copper(II) hexacyanoferrate(III) (CuHCF) modified carbon paste electrode was used for the electroanalytical determination of pyridoxine (vitamin B6) in pharmaceutical preparations, using cyclic voltammetry. Diverse parameters were investigated for the optimization of the sensor response, such as composition of the electrode, electrolytic solution, effect of pH, scan rate of potential and interferences. The optimum conditions were found at an electrode composition of 20% CuHCF, 55% graphite and 25% mineral oil (m/m) in an acetate buffer (pH 5.5) containing 0.05 mol L-1 of NaCl. The range of determination of pyridoxine was from 1.2 x 10-6 to 6.9 x 10-4 mol L-1. The procedure was successfully applied to the determination of vitamin B6 in formulation preparations. The CuHCF modified carbon paste electrode gave results comparable to those obtained using spectrophotometry.
Palabras llave : modified carbon paste electrode; copper(II) hexacyanoferrate(III); voltammetric determination; pharmaceutical preparations.