Diamond paste-based electrodes for the determination of sildenafil citrate (Viagra)

摘要

Three types of monocrystalline diamond: natural diamond 1 A mu m, synthetic diamond 50 A mu m (synthetic-1), and synthetic diamond 1 A mu m (synthetic-2) were used for the design of diamond paste electrodes for the determination of sildenafil citrate (Viagra) using square wave voltammetry. The linear concentration ranges recorded for sildenafil citrate when natural diamond, synthetic-1, and synthetic-2 based electrodes were used were between 10(-12) and 10(-8), 10(-12) and 10(-9), and 10(-11) and 10(-9) mol/L, respectively. Low detection limits which lie between 0.1 and 1 pmol/L proves the sensitivity of the electrodes. It was found that sildenafil citrate yielded a peak at about +0.175 A +/- 0.025 V (versus Ag/AgCl) for all the electrodes. Sildenafil citrate was determined with high reliability from its pharmaceutical formulation.