The method is applicable to antimony contents between 0.001 and 0.1 % (m/m) in all types of copper and copper alloys listed in International Standards. The range of application may be extended by appropriate modification of the mass of the test portion, the extraction volume and the cell path length. Specific proposals to cover lower and higher concentrations are in preparation. ISO 5956 specifies principle, reagents, apparatus, procedure, expression of results and test report.