Fast cathodic stripping analysis with ultramicroelectrodes

Hemispherical ultramicroelectrodes (2.5–12.5 μm in radius) fabricated from silver or amalgamated copper, gold or platinum were used in the cathodic stripping of various anions. A comparison is presented between the results obtained using electrodes of a conventional size at slow sweep rates (ca. 100 mV s^?1) and those obtained using ultramicroelectrodes under fast linear-sweep conditions (ca. 700 V s^?1). Problems in maintaining reproducible electrode surfaces under various experimental conditions are discussed. In addition, the benefit of using electrodes of microscopic dimensions is illustrated by their utilization in the analysis of very small volumes of analyte that result from a solvent back-extraction process.