Jump to main content
Jump to site search

Issue 10, 2012
Previous Article Next Article

Apparatus for in situ monitoring of copper in coastal waters

Author affiliations


Apparatus is designed and tested to determine metals in situ in seawater. Voltammetry with a vibrating gold microwire electrode (VGME) is combined with a battery powered potentiostat and a processor board and is tested for in situ monitoring of copper (Cu) in coastal waters. The VGME was combined with solid state reference and counter electrodes to make a single vibrating probe which was rated up to a depth of 40 m. The measuring mode for Cu was square-wave anodic stripping voltammetry whilst dissolved oxygen (DO) was monitored by a linear sweep scan in a negative potential direction. The working electrode was reactivated between measurements using a suitable potential sequence. The novelties of this work are the field-testing of apparatus incorporating a VGME for copper monitoring, which eliminates the need for pumping and reagents, but has sufficient sensitivity for low ambient levels of copper, and the use of a novel potential sequence to stabilise the response over a long time period. The apparatus has a measuring time of about 6 weeks and a measuring frequency of 12 h−1. Measurement is reagent-free and power use is low as no pump is required. Experiments are carried out to test the stability of response of the system at various temperatures and its robustness with respect to long-term copper monitoring. Preliminary data were obtained during autonomous deployment over several weeks on a buoy in the Irish Sea. Vertical movement of the buoy caused individual measurements to have a variability of about 15%. It was found that longer term variability of the electrode could be minimised by normalisation of the Cu response over that of DO as the response was related to diffusion through the electrode surface which was similarly affected. The detected fraction of Cu (labile Cu) amounted to 1.5–4 nM during different deployments at a total Cu concentration of ∼10 nM. The same ratio was found by voltammetry in samples taken to the laboratory. The new apparatus has demonstrated that metals in coastal waters can be monitored at trace level, much facilitating the monitoring of outfalls and local water contamination. Because of its sensitivity the apparatus would be of use in estuarine as well as coastal waters, with the aim of monitoring intermittent variability in the copper concentration.

Graphical abstract: Apparatus for in situ monitoring of copper in coastal waters

Back to tab navigation

Publication details

The article was received on 11 Jun 2012, accepted on 14 Aug 2012 and first published on 16 Aug 2012

Article type: Paper
DOI: 10.1039/C2EM30460K
J. Environ. Monit., 2012,14, 2793-2802

  •   Request permissions

    Apparatus for in situ monitoring of copper in coastal waters

    C. S. Chapman, R. D. Cooke, P. Salaün and C. M. G. van den Berg, J. Environ. Monit., 2012, 14, 2793
    DOI: 10.1039/C2EM30460K

Search articles by author