Voltammetric determination of dipyrone using a N,N'-ethylenebis(salicylideneaminato)oxovanadium(IV) modified carbon-paste electrode

Abstract

A preparação e a caracterização eletroquímica de um eletrodo de pasta de carbono modificado com o complexo N, N´-etilenobis(salicilidenoaminato) de oxovanádio(IV) ([VO(Salen)]), como também o seu comportamento eletrocatalítico na oxidação da dipirona foi investigado. O comportamento eletroquímico do eletrodo modificado e a eletrooxidação da dipirona foram estudados usando a voltametria cíclica. A resposta voltamétrica do eletrodo modificado é baseada em duas reações. Uma relacionada com a oxidação eletroquímica do centro metálico do complexo [VO(Salen)] e a outra que envolve o processo redox entre centro metálico do complexo oxidado e a dipirona. A melhor resposta voltamétrica foi observada para uma composição do eletrodo de 25% (m/m) [VO(Salen)] em solução eletrolítica de KCl para pH entre 5,5 a 8,0 e uma velocidade de varredura de 10 mV s -1 na presença de dipirona. Uma resposta voltamétrica linear para dipirona foi obtida no intervalo de concentração de 9,9 x 10 -6 a 2,8 x 10 -4 mol L -1 , com um limite de detecção de 7,2 x 10 -6 mol L -1 . Entre os diversos compostos testados como interferente, somente o ácido ascórbico apresentou alguma interferência. O eletrodo proposto é útil para o controle de qualidade e a análise rotineira de dipirona em formulações farmacêuticas.The preparation and electrochemical characterization of a carbon paste electrode modified with N,N'-ethylenebis(salicylideneiminato)oxovanadium(IV) complex ([VO(Salen)]) as well as its behavior as electrocatalyst toward the oxidation of dipyrone were investigated. The electrochemical behavior of the modified electrode and the electrooxidation of dipyrone were explored using cyclic voltammetry. The voltammetric response of the modified electrode is based on two reactions. One electrochemical related to the oxidation of the metallic center of the [VO(Salen)] and the other involving the chemical redox process involving the oxidized form of the complex and the reduced form of dipyrone. The best voltammetric response was observed for a paste composition of 25% (m/m) [VO(Salen)], KCl solution pH from 5.5 to 8.0 as the electrolyte and potential scan rate of 10 mV s -1 in the presence of dipyrone. A linear voltammetric response for dipyrone was obtained in the concentration range from 9.9 x 10 -6 to 2.8 x 10 -3 mol L -1 , with a detection limit of 7.2 x 10 -6 mol L -1 . Among of several compounds tested as potential interference, only ascorbic acid presented some interference. The proposed electrode is useful for the quality control and routine analysis of dipyrone in pharmaceutical formulations.

Analysis of sulfamethoxazole by square wave voltammetry using new carbon paste electrode

“…An irreversible two-electron oxidation voltammetric peak appeared in both cases when 0.005 mol L -1 SMX was present in the solution [29,40]. Also, much lower background current that was obtained for the CPE as compared with the solid glassy carbon, suggests that the proposed CPE electrode could be more sensitive for SMX oxidation [6][7][8][9][10][11][12][13][14][15][16]. The higher background current observed for the glassy carbon electrode in Figure 5B stems from the oxygen evolution [43].…”

“…The following electrolyte solutions were used in this research: 0.1 mol L -1 potassium chloride (Synth), 0.1 mol L -1 sodium nitrate containing 0.01 mol L -1 potassium ferricyanide, 0.1 mol L -1 sodium perchlorate; 0.05 mol L -1 sulfuric acid (Merck)/methanol in 70:30 % (v/v) ratio and 0.04 mol L -1 BrittonRobinson (BR) buffer, pH 2.18, prepared by mixing 0.04 mol L -1 boric acid (Carlo Erba), acetic acid and orthophosforic acid (Merck). Mixtures of graphite powder (particle size = 19.2-168.5 µm, Analítica) and mineral oil (Nujol, União Química) were used to prepare the carbon paste [14,16].…”

“…This electrode consists of a mixture of carbon powder and a non-electroactive liquid binder and offers a broad potential window, low residual current (background), unique surface characteristics, low cost, and versatile preparation [6][7][8][9][10][11][12][13][14][15][16]. For this reason, CPE has been widely employed to determine the sulfamethoxazole (SMX) by the voltammetric analysis.…”

Simultaneous voltammetric determination of dypirone and paracetamol with carbon paste electrode and multivariate calibration methodology

“…Perez-Ruiz et al 41 also observed the same electrochemical behavior for dypirone using a glassy carbon electrode and a carbon paste electrode respectively. According to Teixeira et al, 45 the first electrochemical oxidation peak of the dypirone is related to the methylamino-Nmethanesulphonate group.…”

Development and validation of a multivariate calibration model for determination of dipyrone in oral solutions by near infrared spectroscopy

“…DIP has also been determined in pharmaceutical formulations by HPLC, 4,5 UV-Visible spectrophotometry, [6][7][8][9][10] turbidimetry, 11 chemilumimetry, 12,13 amperometry 14 and voltammetry. 15,16 The most of these methods involve cumbersome steps, such as derivatization reactions, previous separations, solvent extraction, or sample filtration. Vol.…”