Anodic stripping voltammetry at mercury films deposited on ultrasmall carbon-ring electrodes

D. K Y Wong, Andrew G. Ewing*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

33 Citations (Scopus)

Abstract

Anodic stripping voltammetry of lead and cadmium without deliberately added electrolytes has been studied at uttrasmall carbon-ring electrodes following In situ deposition of mercury. The stripping of lead has been studied In detail to Investigate the dependence of stripping peak current on experimental parameters such as potential scan rate, preconcentratlon duration, deposition potential, concentration of Hg+ during deposition, and concentration of Pb2+. Anodic stripping voltammetry In solutions without deliberately added supporting electrolyte avoids problems associated with Impurities Introduced when electrolyte Is added. These impurities appear to be highly Important when Pb2+ analysis is carried out in dilute solutions. In addition, a unique effect Is observed when relatively low concentrations of Hg+ (1.0 × 10-6 M) are used for the In situ deposition step. When low Hg+ concentrations are used, the stripping current does not decrease as rapidly as expected as the concentration of Pb2+ is reduced. The slope of the log-log plot of peak current vs Pb2+ concentration is significantly less than unity, but the calibration plot is linear, and the resulting enhanced peak currents at low Pb2+ concentrations make stripping analysis possible at extremely low concentrations. Concentrations as low as 3.2 × 10-11 M of Pb2+ have been examined.

Original languageEnglish
Pages (from-to)2697-2702
Number of pages6
JournalAnalytical Chemistry
Volume62
Issue number24
Publication statusPublished - 15 Dec 1990
Externally publishedYes

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