ISO 778:2005 specifies the procedure for the determination of acid-soluble copper by atomic absorption spectrometry or by plasma emission spectrometry.
It is applicable to all types of paper, board and pulp.
It specifies a method to determine the acid-soluble part of the incineration residue, i.e. that part of the ignition residue obtained after incineration which is soluble in hydrochloric acid. If the residue is completely soluble, the result obtained by the procedure specified in ISO 778:2005 is taken as the total amount of copper in the sample. The limit of determination is normally 0,1 mg/kg of paper, board or pulp, but it depends on the spectrometer used.