Spectroelectrochemical Sensing Based on Attenuated Total Internal Reflectance Stripping Voltammetry. 1. Determination of Lead and Cadmium

Abstract

The electrodeposition and subsequent stripping of lead and cadmium on an indium tin oxide (ITO) optically transparent electrode (OTE) were monitored by attenuated total internal reflectance. Light passing through the ITO-OTE is attenuated proportionally to the concentration of metal ion and deposition time. The wavelength dependence of the optical responses of deposited Pb and Cd was determined; optimal performance based on maximum sensor absorbance was at 750 nm for Pb and at 400 nm for Cd. Calibration curves were obtained over a range of 5 x 10(-8) to 5 x 10(-5) M and 1 x 10(-9) to 1 x 10(-5) M for Pb and Cd, respectively, using change in absorbance that accompanied deposition and subsequent stripping of the electrodeposited metal from the ITO.

Bare and Polymer-Coated Indium Tin Oxide as Working Electrodes for Manganese Cathodic Stripping Voltammetry

“…32,35 ITO has been used for spectroelectrochemical stripping voltammetry where an optical change associated with the stripping of preconcentrated metal is used as the analytical signal. 37–39 However, neither bare ITO nor SSEBS coated ITO have ever been used as an electrode material for CSV of Mn 2+ .…”

Spectroelectrochemical Sensing: Current Trends and Challenges

“…Therefore, the sensitivity is slightly higher. Finally, attenuated total reflection mode is another interesting approach in which the light beam interrogates the solution from the external face of the electrode. Therefore, as in the normal transmission mode, the electrode material is also limited.…”

A spectroelectrochemical approach to the electrodeposition of bismuth film electrodes and their use in stripping analysis

“…Moreover, spectroelectrochemistry has proven to be useful for quantification via both electrochemical and spectroscopic principles. Some of the spectroelectrochemical studies have been performed with optically transparent electrodes (OTEs), such as metal minigrids with mercury thin films plated on them [16,17] or indium tinoxide (ITO) electrodes where the chemical compounds are directly deposited on them [18][19][20]. In contrast, other spectroelectrochemical stripping experiments have been carried out with solid electrodes such as glassy carbon electrodes [21][22][23].…”

“…Depending on the electrode, different light beam configurations can be used, such as normal incidence to an OTE [16,17], attenuated total internal reflectance [18][19][20], or parallel incidence to the working electrode surface [21][22][23]. Until now, stripping spectroelectrochemistry has been applied to determination of toxic heavy metals, including their mixtures, namely copper [21,22], lead and cadmium [18], mercury and lead [19], or cadmium and copper [20]. However, none of the existing spectroelectrochemical stripping methods has exploited the great potential of bismuth film electrodes.…”