CUPFERRON SEPARATION FOR THE DETERMINATION OF TANTALUM IN HIGH-PURITYIRON AND LOW-ALLOY STEEL BY ICP-AES

For the determination of Ta (> 0.0005 mass %) in iron and low-alloy st eel spectrophotometric methods, e.g., after the extraction of the Ta-V ictoria Blue B complex by benzene, are generally used. To avoid the ap plication of poisonous benzene as extracting solvent and to improve th e detection power, an ICP-AES method after the separation of Ta by cop recipitation with cupferron has been developed. The detection limit (3 sigma) of 0.6 mu gTa/g is lower in comparison with spectrophotometric methods. Therefore, the method also allows the determination of Ta-co ncentrations in the mu g/g-range in high-purity iron.