This document specifies a spectrophotometric method for the determination of the phosphorus content in nickel, ferronickels and nickel alloys between 0,000 5 % (by mass) and 0,05 % (by mass).

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