An Oscillating and Renewing Silver Electrode for Cadmium and Lead Detection in Differential Pulse Stripping Voltammetry

✍ Scribed by Øyvind Mikkelsen; Knut H. Schrøder

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: English
• Weight: 134 KB
• Volume: 13
• Category: Article
• ISSN: 1040-0397
• DOI: 10.1002/1521-4109(200105)13:8/9<687::aid-elan687>3.0.co;2-s

✦ Synopsis

Issues concerning the use of mercury electrode in environmental analyses has led to considerable research effort aimed at ®nding alternative tools with acceptable performance. A renewing silver working electrode is investigated. This system has shown a good response to lead and cadmium. Concentrations as low as 10 mg L À1 have been detected for both ions in 0.1 M HCl solutions. The system shows also little interference from copper. A detection limit of 0.5 mg L À1 is estimated for these systems. The electrode system may be used repeatedly without maintenance over a considerable period of time as a new silver ®lm is formed prior to each scan. The silver electrode has been excited, oscillated with both triangular and sinusoidal audio frequency waves. The results indicate that the reproducibility of the response is increased when the electrode is oscillated sinusoidally. A study of the oscillating frequency has also been carried out. The result shows that the detection sensitivity improved considerably when low frequencies typically in the range 40 to 80 Hz are used. Good detection sensitivity, along with the simplicity of use and maintenance renders this system potentially attractive for use in online and ®eld instruments.