Copper is added to steel in amounts greater than 0.2% but less
than 1.5% as it strengthens, hardens and reduces corrosion of the
product. The amount of copper in a steel product is determined by
digesting the steel product with strong acid, converting all copper
species to the Cu+1 ion, complexing the Cu+1 ion to form a light
absorbing species by reaction with neocuproine, and extracting the
coloured complex with isoamyl alcohol for analysis by UV/VIS
spectrophotometry at the 454...