Determination of vitamin B6 (pyridoxine) in pharmaceutical preparations by cyclic voltammetry at a copper(II) hexacyanoferrate(III) modified carbon paste electrode

Abstract

Um eletrodo de pasta de carbono modificado com o complexo de hexacianoferrato(III) de cobre(II) (CuHCF) foi utilizado na determinação eletroanalítica de piridoxina (vitamina B 6 ) em formulações farmacêuticas usando voltametria cíclica. Diversos parâmetros, tais como: composição do eletrodo, melhor solução eletrolítica, efeito do pH, velocidade de varredura de potenciais e interferentes sobre a resposta do eletrodo modificado, foram estudados. As melhores condições foram encontrados para uma composição de eletrodo de 20% de CuHCF ( m /m), 55% de grafite ( m /m) e 25% óleo mineral ( m /m) em tampão acetato (pH 5,5) contendo 0,05 mol L -1 de NaCl. O intervalo de concentração para determinação de piridoxina foi 1,2 x 10 -6 a 6,9 x 10 -4 mol L -1 . O procedimento foi aplicado na determinação de vitamina B 6 em formulações farmacêuticas e os resultados obtidos com o eletrodo de pasta de carbono modificado com CuHCF foram comparados com os de espectrofotometria.A copper(II) hexacyanoferrate(III) (CuHCF) modified carbon paste electrode was used for the electroanalytical determination of pyridoxine (vitamin B 6 ) 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 B 6 in formulation preparations. The CuHCF modified carbon paste electrode gave results comparable to those obtained using spectrophotometry.

Voltammetric determination of vitamin B6 (Pyridoxine) using multi wall carbon nanotube modified carbon-ceramic electrode

“…5B) and then decreases at higher pHs. On the other hand, the anodic peak current of pyridoxine at MWCNT/CCE shows a hill shaped variation with pH in the range of 2.5-11.0 [14,15,28,30]. A current decrease was observed when pH of the solution is lower than 5.0 (pH<pK a1 ), due to the formation of the pyridoxine acidic form (pK a1 =5.0 and pK a2 =8.96) [31,32].…”

“…The determination of vitamin B 6 and its separation in pharmaceutical preparations and food with amperometric electrochemical detection, using a carbon disc electrode as an electrochemical detector in chromatography [12] and capillary electrophoresis [13], have also been reported. The literature also reports that pyridoxine was studied in pharmaceutical preparations by cyclic voltammetry using carbon paste electrodes modified with copper (II) hexacyanoferrate (III) [14] and with vanadyl (IV)-Salen complex [15]. Furthermore, there are reports where the glassy carbon electrodes have been modified using various modifiers such as a novel carbon nanotube [16] and polymethylene blue [17] and we have reported the electrocatalytic oxidation of pyridoxine on an aluminum electrode modified with metallic palladium particles/iron (III) hexacyanoferrate (II) film as a chemically modified electrode for the determination of pyridoxine [18].…”

New electrode architectures based on poly(methylene green) and functionalized carbon nanotubes: Characterization and application to detection of acetaminophen and pyridoxine

“…[21], and was determined here by differential pulse voltammetry (DPV) and fixed potential amperometry. Pyridoxine, one of the compounds of the vitamin B6 group, was also electrochemically determined; several methods exist for the determination of vitamin B6 in pharmaceutical formulations [22], electrochemical ones also having been reported [23][24][25][26].…”

Voltammetric determination of pyridoxine (vitamin B6) in drugs using a glassy carbon electrode modified with chromium(III) hexacyanoferrate(II)

“…7 Recently, several works involving the use of modified electrodes in voltammetry have been published. [8][9][10] The working electrodes may be modified to improve the analytical signal, the detection range, the sensitivity, and the selectivity of this technique. The determination of PN in drugs using a carbon paste electrode modified with Cu II hexacyanoferrate(III) has been proposed.…”