Differential pulse voltammetry

This chapter presents an overview of anodic stripping voltammetry (ASV) and differential pulse polarography (DPP) and their applications in the areas of environmental soil analysis. Normal pulse polarography (NPP) is the simplest of the pulse techniques where, at the start of each pulse, no current flows. DPP is similar to NPP except that a difference in current is measured, and gives a peak waveform instead of a wave. In DPP the same square-wave pulse is applied to the drop, but the pulses have constant amplitude that are superimposed on a relatively slow linear direct current (DC) potential sweep. For a two-electron reaction, DC polarography has a sensitivity of a few micromolar. The chapter discusses the application of DPP to analysis, speciation, and complexation research. Modern instruments offer alternating current polarography, fast linear scan voltammetry and dual-cell operation in addition to DC polarography, NPP, DPP, ASV, and differential pulse anodic stripping voltammetry.