Solid Amalgam Electrodes and Alloy Electrodes for Electroanalysis

Oyvind Mikkelson ,  Silje M. Skogvold ,  Knut H. Schroder 

Department of Chemistry, Norwegian University of Science and Technology (NTNU), Trondheim N - 7491, Norway

Abstract

Liquid mercury is a unique material for the working electrode in voltammetry because of its high negative potential of hydrogen evolution, its ability to form liquid amalgams and the possibility to regenerate continuously a new electrode surface simply by dripping out a new mercury drop from a glass capillary. However, mercury is considered as a toxic heavy metal and, therefore, should be avoided in online apparatuses for use in field.
Because voltammetry is very suitable for field and remote monitoring, issues concerning the use of mercury electrodes in environmental analyses have led to considerable research effort aimed at finding alternative to mercury electrode materials with comparable or better performance.
In this presentation an overview of several compact (non-film) solid amalgam and alloy electrodes will be given, including the dental amalgam electrode [1, 2], silver electrodes alloyed with only a few percent of mercury, silver-bismuth electrode, gold-bismuth electrode, silver-copper electrodes, etc.
The accessible potential windows in different electrolyte solutions for these electrodes will be systematically presented and discussed as well as their possibility for use in detection of several different metals including cobalt, nickel, zinc, cadmium, iron, led, copper, mercury, and silver in low ppb and sub ppb level in real samples will be given. In particular, solid amalgam electrodes are very promising, with acceptable low toxicity, for use in field measurements. Assessment of the toxicity risk and the long-time stability for remote and unattended monitoring will be discussed.
The differences between homogeneous amalgam electrodes, prepared by using techniques known from dental clinical practice, and mercury film or mercury layer electrodes on solid substrates will be reviewed as well. Analogous comparisons will be presented for compact (non-film) alloy electrodes.

Key words: Anodic stripping voltammetry, Solid electrodes, Dental amalgam, Mercury electrode, Heavy metals, Alloy.

REFERENCES
1. O. Mikkelsen and K. H. Schroder, Electroanalysis 15 (2003) 679.
2. O. Mikkelsen and K. H. Schroder, Electroanalysis (2003) in press.

Legal notice
  • Legal notice:

    Copyrighted materials, (c) Pielaszek Research, all rights reserved.
    The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced, stored in or introduced into a retrieval or caching system, or transmitted in any form or by any means (electronic, mechanical, photocopying, recording or otherwise), or for any purpose, without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
    In every case, proper references including Author(s) name(s) and URL of this webpage: http://science24.com/paper/1254 must be provided.

 

Related papers
  1. Electrochemical Properties and Range of Application of Silver-bismuth Alloy Electrodes. Detection of Zinc, Cadmium and Lead in Real Samples at Sub-ppb Concentration Levels
  2. Determination of Silver and Copper at Low ppb and sub-ppb Concentration Ranges in Mixture in Natural Water by Using Anodic Stripping Voltammetry at a Gold-bismuth Alloy Electrode

Presentation: Keynote lecture at SMCBS 2003 Workshop, by Oyvind Mikkelson
See On-line Journal of SMCBS 2003 Workshop

Submitted: 2003-10-07 14:00
Revised:   2009-06-08 12:55
Google
 
Web science24.com
© 1998-2021 pielaszek research, all rights reserved Powered by the Conference Engine