This part of ISO 6101 specifies an atomic absorption spectrometric method for the determination of the copper content of rubbers. The method is applicable to raw rubber and rubber products having copper contents above 1 ppm. Copper contents below this limit can be determined, provided that suitable adjustments are made to the mass of the test portion and/or to the concentrations of the solutions used. The use of the standard additions method can lower the bottom limit of detection.