Rapid spectrophotometric determination of copper in iron,steel and ferrous alloys

A rapid spcctrophotometric mcthod for the determination of copper in iron, steel and ferrous alloys without separating the copper has been developed. The sample is dissolved in acid and ammonium citrate is added to complex the iron and other alloying elements. The pH is then adjusted to 8.0–9,5 with ammonium hydroxide. A solution of bis-cyclohexanone-oxalyldihydrazone ia finally added and the absorbance of the blue copper complex formed is measured.