New voltammetric approach to the quantitative estimation of sildenafil citrate in tablets using disposable pencil graphite electrode

The voltammetric behavior of sildenafil citrate (SC) was studied through differential pulse stripping voltammetry. The best sensitivity, optimal experimental conditions and settings for the voltammetric method development were obtained by applying experimental design and optimization methodology to the designed sample runs at different accumulation times, accumulation potentials and pHs. The linearity over the concentration range 1 × 10-7 M-8 × 10-6 M for SC was determined and the limit of detection (LOD) was 3.1 × 10-8 M. For the method ability and validity, mean recovery result and relative standard deviation were found to be 99.3% and 2.19%, respectively. The method was applied to the determination of SC in pharmaceutical and plasma samples.