Application Bulletin no. 43 describes the polarographic determination of copper. For copper concentrations of 10 mg/L and below, however, colorimetric methods are also used, particularly in water analysis.
The method using sodium diethyldithiocarbamate can be employed down to a minimum limit of 0.01 mg/L Cu, but suffers from the drawback that the determination can also be affected by other metal ions.
The method using neocuproine has a minimum concentration limit of 0.1 mg/L Cu, but has the advantage of being unaffected by ions of other metals.