ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Voltammetric determination of B1 and B6 vitamins using a pencil graphite electrode

Iulia Gabriela David, Mihai-Alexandru Florea, Oana Georgiana Cracea, Dana Elena Popa, Mihaela Buleandra, Emilia Elena Iorgulescu, Vasile David, Irinel Adriana Badea, and Anton Alexandru Ciucu

Department of Analytical Chemistry, Faculty of Chemistry, University of Bucharest, Panduri Av. 90–92, District 5, Bucharest-050663, Romania

E-mail: antonciucu@yahoo.com

Abstract: Due to the importance of B₁ and B₆ vitamins for human health it is useful to develop new cheap and rapid methods for their determination. Voltammetric behavior of these vitamins on a pencil graphite electrode was investigated using cyclic voltammetry in different media. Direct quantitative determination of the two vitamins, one in the presence of the other, was done by differential pulse voltammetry. Vitamin B1 was electroactive only in a NaOH solution generating two irreversible oxidation peaks; the first peak obtained at 250 mV is well-defined and was used in quantitative determinations. In case of vitamin B6, a well-defined oxidation peak was observed in all investigated supporting electrolytes except for HCl. The linear concentration ranges were 10⁻⁵- 10⁻³ M for vitamin B1 in a NaOH solution and 5 × 10⁻⁶-10⁻³ M for vitamin B6 in an acetate buffer solution. The obtained detection limits were 5.34 × 10⁻⁶ M and 2.81 × 10⁻⁶ M for vitamin B1 and vitamin B6, respectively. The developed method is simple and rapid and it was successfully applied in the determination of the two vitamins in pharmaceuticals.

Keywords: pencil graphite electrode – B1 and B6 vitamins – voltammetry – pharmaceuticals

Full paper is available at www.springerlink.com.

DOI: 10.1515/chempap-2015-0096

Chemical Papers 69 (7) 901–910 (2015)