Spectrophotometric determination of alloying elements at the major and minor concentration levels

Abstract

Several methods for the determination of alloying elements at the major and minor concentration levels were described. The determination of copper was based on the copper-aquo complex formation in nitric acid media. This method was successfully applied to copper-zinc alloys with the coefficient of variation of less than 0.2%. The spectrophotometric determination of phosphorus in iron-phosphorus and nickel-phosphorus alloys was carried out by the phosphovanadomolybdate method. Antimony { (0.116) %} in antimony-iron alloys was determined as follows. Samples were dissolved with nitric and sulfuric acids. Antimony was allowed to form iodide complex in 3 N sulfuric acid by the addition of potassium iodide and sodium hypophosphite. The absorbance was measured at 425 nm. When the sample contained bismuth, the antimony was extracted into benzene. After the back extraction with sulfuric acid (1 + 20), the antimony was determined as described above.