Sulfadiazine determination in pharmaceuticals by electrochemical reduction on a glassy carbon electrode

Abstract

Sulfadiazina foi quantificada em duas amostras de produtos farmacêuticos usando voltametria de onda quadrada. O sinal analítico foi obtido por redução em vez de oxidação da sulfa sobre eletrodo de carbono vítreo. A determinação eletroanalítica foi realizada em solução-tampão Britton-Robinson 0,04 mol L -1 com pH 6,8. A redução irreversível da sulfadiazina foi observada em -1,49 V vs. Ag/AgCl. A curva analítica foi obtida na faixa de concentração entre 62,7 e 340 µmol L -1 (r = 0,9986) e o limite de detecção foi 10,9 µmol L -1. Para uma amostra analisada, os valores de recuperação ficaram entre 94,9 e 101,1%, enquanto para a outra amostra foram entre 96,0 e 104,6%, indicando que a composição da matriz não interfere nos resultados analíticos. A exatidão do método eletroanalítico foi comparada com o método padrão de titulação amperométrica.Sulfadiazine was quantified in two samples of pharmaceutical preparations by square-wave voltammetry. The analytical signal response was obtained by electrochemical reduction instead of oxidation of the sulfa drug at a glassy carbon electrode. The determination was carried out in 0.04 mol L -1 Britton-Robinson pH 6.8 buffer solution. Sulfadiazine reduction was observed at -1.49 V vs. Ag/AgCl in one well-resolved irreversible peak. The analytical curve was obtained in the concentration range of 62.7 to 340 µmol L -1 (r = 0.9986) with a detection limit of 10.9 µmol L -1 . For one sample analyzed, recovery values were in the range of 94.9 to 101.1%, while for the other sample they were within 96.0 to 104.6%, indicating no matrix interference effects on the analytical results for both sulfadiazine samples. The accuracy of the electroanalytical method was compared to the standard amperometric titration method.

Application of bismuth-film electrode for cathodic electroanalytical determination of sulfadiazine

“…2B matches the pK a of the sulfonamide group (-SO 2 NH-). The value found (7.5) is one unit higher than that reported in the literature [30,32]. The reduction of sulfonamides at bismuth electrodes has not yet been studied and there are few reports on this reaction at mercury electrodes.…”

“…Owing to concerns over the electroanalytical determination of sulfa drugs, methods using both oxidation [16][17][18][19][20][21][22][23] and reduction [24][25][26][27][28][29][30] reactions have been reported. Sulfadiazine (4-amino-N-2-pyrimidinylbenzenesulfonamide), together with sulfamethoxazole, is the sulfonamide antibiotic most used in human and veterinary medicine.…”

“…For example, detection limits of 44 [21] and 50 nmol L −1 [19] were achieved using BDD electrodes as amperometric detectors in HPLC systems. In relation to the reduction reaction for sulfadiazine determination, a detection limit of 0.5 mol L −1 has been obtained by direct current stripping voltammetry at a hanging mercury electrode [24], 4.9 mol L −1 by differential-pulse polarography at a mercury electrode [26], 4.0 mol L −1 by square-wave voltammetry at a glassy carbon-poly(3-methylthiophene) electrode [28] and 10.9 mol L −1 by square-wave voltammetry at a simple glassy carbon electrode [30].…”

Carbon Paste Electrodes Modified with Sulfated Polysaccharide Porphyran: Potential Applications in the Electroanalytical Determination of Sulfonamides

“…1,4-6 Além destas propriedades farmacológicas atrativas, tais polissacarídeos encontram também aplicações em diversas áreas da biotecnologia e da engenharia. 7 As porfiranas (PFR) constituem uma classe bem estudada de PLS obtidos por extração aquosa a partir de algas vermelhas das espécies Porphyra e Bangia 5 [33][34][35][36] No que se refere ao conhecimento dos autores, não existem reportados na literatura até o momento exemplos da aplicação da PFR na modificação de eletrodos para aplicação na eletroanálise de fármacos. Neste sentido, o presente trabalho tem por objetivo desenvolver e caracterizar eletrodos de pasta de carbono (EPC) modificados com o polissacarídeo sulfatado PFR, sendo estes aplicados para a determinação eletroanalítica de dois antibióticos da classe das sulfonamidas: sulfacetamida sódica (SFC) e sulfadiazina (SFD).…”

Determination of sulfonamides in milk samples by HPLC with amperometric detection using a glassy carbon electrode modified with multiwalled carbon nanotubes

“…Thus, in this way, the voltammetric behavior of eight sulfonamides at the glassy carbon electrode (GCE) was studied and low detection limits were obtained . The same electrode was used in the oxidation and reduction of sulfadiazine in pharmaceuticals with good results. A similar study for the electroanalytical oxidation of sulfamerazine was carried out by Pingarrón et al .…”