| Abstract: | Abstract The voltammetric behavior and measurement of nicardipine at the glassy carbon, carbon paste and hanging mercury drop electrodes are discussed. Cyclic voltammetry is used to elucidate the redox mechanism. Nicardipine is shown to adsorb on carbon electrodes, with the surface species retaining its electroactive characteristics. The adsorptive accumulation serves as a preconcentration step which improves the voltammetric measurement with respect to selectivity and sensitivity. Coupling this with a medium-exchange step eliminates interferences due to solution-phase electroactive species and permits direct measurement in urine. The inherent sensitivity of differential pulse voltammetry at the mercury electrode permits convenient measurement at the submicromolar level, with detection limit of 2 × 10?8M. Amperometric detection for a flow injection system is illustrated. |
