Novel two methods for determination of trace metals in steel have been developed by combining ion-exchange separation and atomic spectrometry. Sample is decomposed with hydrochloric acid and hydrogen peroxide. For the determination of Mo of 0.01 m/m % level, the sample is loaded as dilute sulfuric acid solution on a column of anion-exchanger TEVA resin. Iron ion passes through the column and Mo ion retained on the column is then recovered by elution with nitric acid, followed by quantification by inductively coupled plasma atomic emission spectrometry (ICP-AES). For the simultaneous determination of Al, Mn, Ni and Co of 0.001 to 0.1 m/m % level, the sample is loaded as hydrochloric acid-oxalic acid-hydrogen peroxide solution on a cation-exchange resin Bio-Rad AG 50W column. Iron ion passes the column as oxalato-complexes, and Al, Mn, Ni and Co ions retained on the column are eluted with hydrochloric acid to be subjected to the simultaneous determination by ICP-AES (for metals of 0.01 to 0.1 m/m % level) or "one drop" flame atomic absorption spectrometry (for metals of 0.001 m/m level). The analytical results obtained for the steel certified reference materials are in good agreement with certified values and the precision (R.S.D.=1 to 8%) is satisfactory.
