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Sensitivity Enhancements in Stripping Voltammetry from Exposure to Low Frequency Sound
Author(s) -
Mikkelsen Øyvind,
Schrøder Knut H.
Publication year - 1999
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/(sici)1521-4109(199905)11:6<401::aid-elan401>3.0.co;2-6
Subject(s) - anodic stripping voltammetry , reproducibility , electrode , audio frequency , low frequency , voltammetry , analytical chemistry (journal) , materials science , chloride , dropping mercury electrode , sound intensity , chemistry , acoustics , sound (geography) , sound pressure , electrochemistry , chromatography , physics , astronomy , metallurgy
Improving the sensitivity of voltammetric analysis containing low metal concentrations has been attempted by exposure to low frequency sound. It was found that audible sound in the low frequency range, around 100 Hz was very effective for this purpose, with an increase of the analytical signal up to about 300%, without any significant increase in the corresponding noise level. Ordinary stirring has to be avoided during the voltammetric scanning due to the low reproducibility when stirring takes place. Sound exposure, however, can be performed during the entire measurement, and this explains the increased sensitivity. Further it is concluded that sound exposure close to the resonant frequency, has improvement effects at least comparable to stirring, and thus all mechanical stirring can be avoided. Differential pulse anodic stripping voltammetry with a three‐electrode cell system was used with a static mercury drop electrode exposed by low frequency sound, a Pt counter‐electrode and a silver/silver chloride/saturated silver chloride/saturated potassium chloride reference electrode. However, it is presumed that other modes of voltammetry than DPASV would show similar behavior when exposed to audible sound. Low frequency sound is assumed to influence the physical conditions in the vicinity of the electrode by diffusion layer thinning, to increase the surface concentration. Moreover, the simplicity of using audible sound, with high reproducibility of the measurements, makes this analytical method potentially attractive.