ICP-AES Determination of Trace Amount of Niobium in Low Alloy Steel

The sample of low alloy steel (0.500 0 g) was dissolved with mixed acid (20 mL) of HCl and HNO3 (3+1). After cooling, 8.00 mL of H2SO4 was added (evaporate to SO3 white smoke) and the solution was made up to 100 mL with water. Trace amount of niobium in the solution was determined at the analytical spectral line of 319.498 nm by ICP-AES. Linear relationship between values of spectral intensity and mass concentration of niobium was kept in the range of 0.000 25%-0.007 0%, with detection limit of 0.000 43%. The proposed method was applied to the analysis of substantial samples, giving values of RSD′s (n=11) in the range of 2.4%-9.3%. The proposed method was applied to the analysis of standard samples of low alloy steel, giving results in consistency with the certified values with RSD′s (n=11) in the range of 2.7%-8.2%.