This International Standard specifies the procedure for the determination of acid-soluble magnesium, calcium, manganese, iron, copper, sodium and potassium by atomic absorption spectrometry or by plasma emission spectrometry. The acid-soluble element comprises 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. In the case where the residue is completely soluble, the result obtained by the procedure specified in this International Standard is a measure of the total amount of each element in the sample. This International Standard is applicable to all types of paper, board and pulps. The limit of determination depends on the element and on the instrument used.