微波等离子体炬原子发射光谱法测定钢中镍和铬

Determination of nickel and chromium in the steels by microwave plasma torch atomic emission spectrometry

用微波等离子体炬为激发光源,氩气为等离子体工作气体,气动雾化进样,研究了微波等离子体炬原子发射光谱法(MPT-AES)测定钢中镍、铬的方法。考察了微波前向功率、载气流量、工作气流量、氧屏蔽气压力等参数对测定镍、铬的影响,并进行了系统优化;试验了酸度影响及共存离子的干扰情况,使用基体匹配法来消除基体干扰。测定镍、铬的线性范围分别为0.2～100μg/mL和0.5～70μg/mL,检出限分别为45.7 ng/mL,41.5 ng/mL。本法测定结果与国家标准方法测定结果相吻合,RSD(n=11)分别小于2.1%和3.5%。

By means of microwave plasma torch（MPT） as excitation source and Ar as support gas,the determination of nickel and chromium in the steel samples by microwave plasma torch atomic emission spectrometry（MPT-AES）with a pneumatic nebulization sample introduction was devoloped . The experimental conditions including microwave power, flow rate of carrier gas, flow rate of support gas, pressure of oxygen as shield gas were optimized. The effects of acidity and coexistent ions on the determination of nickel and chromium were investigated, and matrix match method was used to overcome matrix interference . The detection limits for nickel and chromium are 45.7 ng/mL and 41.5 ng/mL, the linear ranges for nickel and chromium are 0. 2-100 μg/mL and 0.5-70 μg/mL ,respectively. The determination results of MPT-AES are identical with those obtained by national standard method and the relative standard deviations（n=11）are less than 2.1% for nickel and 3.5% for chromium .