低合金钢样品0.500 0 g经盐酸-硝酸(3+1)混合酸20 mL溶解,稍冷,加入硫酸8.00 mL(蒸发至冒SO3白烟),最后加水定容至100 mL,采用电感耦合等离子体原子发射光谱法在分析谱线为319.498 nm处测定其中的痕量铌。铌的质量分数在0.000 25%~0.007 0%之间与其光谱强度呈线性关系,方法的检出限为0.000 43%。方法用于实际样品的分析铌,测定值的相对标准偏差(n=11)在2.4%~9.3%之间。应用此方法分析了低合金钢标准样品,测定值与认定值相符,测定值的相对标准偏差(n=11)在2.7%~8.2%之间。

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%.