中低合金钢中小于50ppm的铌量之准确测定必须采取预先分离或富集的手段。在利用经典的发射光谱法测定该元素以前可用钨酸钠富集该元素。已经制定出一种富集方法,其测定下限可达15ppm,对含铌18ppm的试样所测得的精确度为17.5±1.5ppm,变动系数为5.34%。 Accurate determination of the amount of niobium of less than 50ppm in low and medium alloy steels must be done by means of pre-separation or enrichment. This element can be enriched with sodium tungstate before the element is determined by classical emission spectroscopy. An enrichment method has been developed that has a lower limit of determination of up to 15 ppm, an accuracy of 17.5 ± 1.5 ppm for a sample containing 18 ppm niobium, and a coefficient of variation of 5.34%.