Chapter 13: Electroanalytical Techniques and Ion Chromatography Check Access

Among the electroanalytical techniques, anodic or cathodic stripping differential pulse voltammetry is widely used. A differential pulse is applied due to its higher sensitivity (as compared to normal pulse voltammetry) and better resolution of individual peaks with close half-wave potentials during stripping with an optimum scan rate usually 0.05 V s⁻¹ and a suitable scan rate to avoid degradation of the signal-to-background ratio. Stripping methods essentially constitute deposition of the analyte on a working electrode for a specified period as an initial step. The initial step of electrodeposition of the analyte from the solution on the working electrode for a specified period affects the pre-concentration of the analyte in stripping methods. Besides, highly sensitive adsorptive and catalytic cathodic stripping voltammetric techniques are also utilized. IC basically involves the separation of anions such as F⁻, Cl⁻, Br⁻, PO₄³⁻, NO₃⁻ and SO₄²⁻ in geochemical exploration, essentially, in hydrogeological samples through an ion exchange separation column containing ion exchange groups with charged functional groups to carry out the separation of ions and their subsequent electronic detection through conductivity measurements. Ion chromatography (IC) offers several advantages such as rapid analysis (time ∼10–20 min) and highly sensitive and selective analysis even in complex samples with high ionic ratios.