The use of ultrasound in the enhancement of the deposition and detection of metals in anodic stripping voltammetry

✍ Scribed by Frank Marken; Thomas O. Rebbitt; Jonathan Booth; Richard G. Compton

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 497 KB
• Volume: 9
• Category: Article
• ISSN: 1040-0397
• DOI: 10.1002/elan.1140090106

✦ Synopsis

The fast electrochemical deposition of both mercury and amalgam films, a crucial step in analytical anodic stripping voltammetry, is demonstrated to occur in the presence of power ultrasound emitted from an immersion horn probe which was placed opposite the working electrode in a conventional three electrode cell. Due to considerably enhanced mass transport the rate of deposition is strongly increased compared to 'silent' conditions. The total amount of mercury adhering to a glassy carbon electrode surface, however, is limited to a 'thin film' of microscopically small droplets of mercury as shown by atomic force microscopy and voltammetry. Due to surface forces induced by ultrasound, abrasion of some of the deposit occurs and after a certain period of time the parallel electro-deposition and abrasion processes reach a 'steady state'.

The deposition of mercury in the presence of Pb2+ or Cu" results in the formation of an amalgam and well-defined, very sharp 'stripping' responses for the oxidation process of the corresponding amalgam were detected. The merit of insonation in analytical electrode preconcentration techniques is dicussed.