Stripping voltammetry with the electrode material acting as a 'built-in' internal standard

The oxidation peak of the bismuth layer of bismuth-film electrodes is used as an internal standard in anodic stripping voltammetry. Such use of the electrode material as a 'built-in' internal standard simplifies the analytical protocol (as it obviates the need for an external standard or long calibration and standard additions procedures) while correcting for run-to-run variations due to uncertainties (e.g., changes in mass transport, surface area, or other variables). The new internal standard strategy relies on common in situ plated film electrodes, where the deposition of both the analyte and electrode material is subject to the same variations. Such one-step quantitation and improvements are illustrated for trace measurements of lead. The use of the intrinsic signal of the system for obtaining the concentration of the target analyte is unique not only for electroanalysis, but for analytical chemistry in general. (C) 2001 Elsevier Science B.V. All rights reserved.