This International Standard specifies a molecular absorption spectrometric method for the determination of the phosphorus content in nickel, ferronickel and nickel base alloys in the range of 0,000 5 % (m/m) to 0,05 % (m/m).

Arsenic, chromium, hafnium, niobium, silicon, tantalum, titanium and tungsten interfere, but the interferences can be avoided by complexation or volatilisation (for Cr). The lowest phosphorus content [0,000 5 % (m/m)] can only be reached in samples with low contents of the interfering elements.