Determination of Trace Metals in Steel by Combining Anion Exchange Separation with ICP-AES( Recent Developments in Analytical Technology and Methodology)

A selective anion-exchange separation in potassium iodide-hydrochloric acid media has been combined with ICP-AES for the determination of trace metals in steel. An appropriate amount of steel sample was decomposed with a mixture of nitric acid, hydrochloric acid and hydrogen peroxide, or a mixture of nitric acid, hydrochloric acid and sulfuric acid, and prepared as a potassium iodide-hydrochloric acid solution containing ascorbic acid to reduce iron(III) to iron(II). The sample solution was passed through a strongly basic anion exchange resin column to remove iron. The trace metals adsorbed on the column were simultaneously eluted with a dilute nitric acid solution and determined by ICP-AES. The proposed method was successfully applied to the determination of Bi, Te, Cu, Pb and Sb at ppm levels in steel reference materials provided by Japan Iron and Steel Federation, and National Institute of Standards and Technology, yielding reasonable results with regard to accuracy and reproducibility.