Determination of Trace Amounts of Rare-Earth Elements in Clean Steel by Inductively Coupled Plasma Optical Emission Spectrometry after Removal of Iron Matrix with Anion-Exchange Resin

Inductively coupled plasma optical emission spectrometry (ICP-OES) was applied to the determination of trace rare-earth elements in clean steel. The steel sample was dissolved with a mixture of hydrochloric acid (HC1), nitric acid (HNO₃), and hydrogen peroxide (H₂O₂), with the solution passing through a column packed with the anion-exchange resin DOWEX 1×8–200. Iron was absorbed selectively on the resin column, and the analytes of interest passed through the column and were effectively separated from the iron matrix. Conditions of separation were optimized. When the sample solution was spiked with 10 μg of the analytes of interest, the recoveries ranged from 88% to 102%, and relative standard deviations were between 6% and 21% (n = 6). The method was successfully applied to the determination of trace amounts of targeted elements in clean steel.