Measurements of low concentrations of diltiazem by adsorptive stripping voltammetry and flow amperometry

Abstract

The voltammetric behaviour and measurement of diltiazem at mercury and carbon electrodes are discussed. Controlled interfacial accumulation of diltiazem on a hanging mercury drop electrode provides the basis for a sensitive adsorptive stripping voltammetric procedure. The effects of various operational parameters on the stripping response are discussed. With 3 min pre-concentration, an 11-fold enhancement of peak current was observed, resulting in a detection limit of 4 × 10^–9M. The anodic response of diltiazem at carbon electrodes was used for amperometric detection for flowing streams. Flow injection measurements yielded a detection limit of 1.5 ng.