Stripping voltammetry for field determination of traces of copper in soil extracts and natural waters

Field analysis is becoming increasingly popular, owing to the commercial availability of portable instruments, fast response and cost-effectiveness. Nevertheless, field analysis requires a careful planning. Voltammetry is particularly suitable for the field determination of trace elements thanks to its sensitivity, simplicity of operation and instrument portability. Therefore, in this work, Anodic Stripping Voltammetry (ASV) was applied to the field determination of Cu(II), as a pilot analyte, in natural water and in a soil extract, and the experiment organization was carefully detailed. Four solid electrodes were previously tested in the laboratory and their performances in terms of precision, linearity, trueness and overall ease of operation were discussed. The well-known Mercury Film Glassy Carbon Electrode (MF-GCE) was selected for field measurements because it yielded the most satisfactory performances. Anyway, the suggestions given in this paper can be useful for other electrodes and other analytes; in particular, a list of the items that should be brought to the site where analysis will be carried out was proposed in order to provide a general guide for the organization of field measurements by voltammetry.