Voltammetric determination of nifedipine at a hanging mercury drop electrode and a mercury meniscus modified silver amalgam electrode

摘要

The voltammetric behavior of nifedipine (NFD) has been studied with two different types of working electrodes (hanging mercury drop mini-electrode (HMDmE) and mercury meniscus silver solid amalgam electrode (m-AgSAE)) using differential pulse voltammetry (DPV). The optimal conditions for DPV determination are: a mixture of Britton-Robinson (BR) buffer pH 8 with methanol in three different ratios (1:1, 9:1, 99:1), respectively, in the concentration range of 0.2 to 20 µmol/L. The limit of quantification (LQ) was found to be 0.12 µmol/L (HMDmE) and 1.2 µmol/L (m-AgSAE). Attempts to increase the sensitivity using adsorptive stripping DPV at both HMDmE and m-AgSAE were not successful. Using the optimum conditions, the practical application of the newly developed method has been verified on the determination of NFD in spiked samples of drinking and river water.