عنوان المقالة: Utility of Electrochemical Sensors for Direct Determination of Nicotinamide (B3): Comparative Studies Using Modified Carbon Nanotubes and Modified β-Cyclodextrin Sensors
Abdoon, Fadam M.; Khaleel, Ali I.; El-Tohamy, Maha F.
الملخص الانجليزي
Highly sensitive and selective electrochemical sensors for potentiometric detection of nicotinamide (NA) were described. Four NA sensors were fabricated in the presence of a polymeric matrix polyvinyl chloride and plasticized using o-nitrophenyloctyl ether (o-NPOE) as a plasticizer. The introduced sensors I and II were coated wire type, prepared with electroactive material nicotinamide-phosphomolybdate (NA–PM), while sensor II was modified using the ionophore 2-hydroxypropyl b-cyclodextrin. Carbon paste type sensors III and IV were fabricated using nicotinamide-phosphotungstate (NA–PT) and sensor IV was modified using carbon nanotubes. The characteristic performance of the fabricated sensors was studied. Nernstian responses of (51.7 ± 0.4, 54.6 ± 0.8, 56.9 ± 0.5 and 59.7 ± 0.2 mV decade–1) for sensors I, II, III and IV, respectively at 25 °C, over drug concentration ranges of 1.0 × 10–6–1.0 × 10–3, 5.0 × 10–7–1.0 × 10–2, 5.0 × 10–7–5.0 × 10–2 and 5.0 × 10–8–1.0 × 10–2 mol L–1 with lower detection limits of 4.4 × 10–7, 2.4 × 10–7, 2.5 × 10–7 and 2.6 × 10–8 mol L–1 for the four mentioned sensors, respectively. A separate solution method was used for the evaluation of the specificity of the fabricated sensors towards the (NA) ions. Coformulated additives, possible interfering species and some related pharmacological action drugs were used and no interference was found. Forced degradation and the stability indicating studies were carried out under different conditions. The fabricated sensors were employed for determination of the tested drug in bulk drug, its pharmaceutical formulations and biological fluids. Statistical treatment was applied to analyze the obtained results and the calculated data were compared with those obtained from other previously published methods.
أ.د. فدعم متعب عبدون | Prof Dr. Fadam Muted Abdoon | 3542