低合金钢样品经磨料粒径小于0.155 mm的氧化锆砂纸打磨，再经乙醇清洗后，采用火花放电原子发射光谱法用于测定低合金钢中痕量铌。选择预燃时间为4 s，分析时间为5 s；选择波长为210.94 nm谱线为铌的分析线，并采用干扰系数加和模式修正钒的干扰。铌的相对谱线强度与其质量分数之间的校准曲线方程为y=0.030 35 x²+0.218 85 x-0.002 525，检出限为0.000 6%。方法应于低合金钢样品分析，测定值的相对标准偏差（n=11）为8.3%~13%；方法用于标准物质中铌的测定，测得值与认定值吻合。

The sample of low alloy steel was polished by abrasive zirconia sandpaper with particle size less than 0.155 mm, and then cleaned by ethanol. Trace amount of niobium in the sample was determined by spark discharge AES. The pre-burning time was selected with 4 s and the analysis time was selected with 5 s. The 210.94 nm spectral line was selected as the niobium analysis line, and the interference coefficient plus mode was used to correct the interference from vanadium. The calibration curve equation between the relative spectral intensity of niobium and its mass fraction was y=0.030 35 x²+0.218 85 x-0.002 525, with detection limit of 0.000 6%. The proposed method was analyzed to the sample of low alloy steel, and values of RSD (n=11) were found in the range of 8.3%-13%. The proposed method was used to the determination of niobium in standard material, giving determining values in accordance with the certified value.