This standard specifies a method for the direct determination of iron, nickel, copper, manganese and mg in metallic calcium by Atomic absirption spectroscopy-tometry, AAS, which is suitable for the preparation of metallic calcium by electrolysis distillation. The lower limits of determination are: iron 20 µg/g, nickel 20 µg/g, copper 10 µg/g, manganese 10 µg/g, mg 20 µg/g. The method dissolves the sample by nitric acid and dilutes it appropriately. Background correction and matrix matching methods are used to quantitatively analyze elements under selected conditions, providing an important basis for impurity control in metallic calcium products.