脉冲熔融-飞行时间质谱法测定钒氮合金材料中氧氮氢

随着人们对痕量杂质元素含量检测要求的逐年提高,提出了一种钒氮合金中氧、氮、氢同时测定的方法。称取0.050 g经处理后的样品,用洗净的镍箔包裹后放入镍篮中,整体投入脱气后的高温石墨套坩埚中,控制分析功率为4.5 kW,以¹²C⁺、¹⁴N⁺、²H⁺作为氧、氮和氢的质谱分析线,实现了脉冲熔融-飞行时间质谱法对钒氮合金材料中氧、氮和氢的同时测定。从实验结果可以看出,在最优的实验条件下,校准曲线的线性相关系数均大于0.999,方法中氧、氮和氢元素的检出限分别为0.02、0.06和0.002 μg/g。将实验方法应用于钒氮合金样品中氧(6.5～94.3 μg)、氮(12～264 μg)、氢(0.10～8.8 μg)元素的测定,测定结果与脉冲熔融-红外/热导法(IR/TCD)基本一致;氧和氮的相对标准偏差(RSD,n=7)均小于9%,氢测定结果的标准偏差(SD,n=7)不大于0.000 5%。

Determination of oxygen,nitrogen and hydrogen in vanadium-nitrogen alloy materials by pulse heating-time of flight mass spectrometry

With the increasing inspection requirements on content of trace impurity elements, a simultaneous determination method of oxygen, nitrogen and hydrogen in vanadium-nitrogen alloy was developed. 0.050 g of sample after treatment was packed with clean nickel foil and put into nickel basket, which was then put into degassed high temperature graphite crucible. The analytical power was controlled at 4.5 kW. The content of oxygen, nitrogen and hydrogen in vanadium-nitrogen alloy materials was simultaneously determined by pulse heating-time of flight mass spectrometry using ¹²C⁺, ¹⁴N⁺ and ²H⁺ as the analytical line, respectively. The experimental results showed that the linear correlation coefficients of calibration curves under optimal conditions were higher than 0.999. The detection limit of oxygen, nitrogen and hydrogen in proposed method was 0.02, 0.06 and 0.002 μg/g, respectively. The proposed method was applied to the determination of oxygen (6.5-94.3 μg), nitrogen (12-264 μg) and hydrogen (0.10-8.8 μg) in vanadium-nitrogen alloy samples. The determination results were basically consistent with those obtained by pulse heating-infrared thermal conductivity detection method (IR/TCD). The relative standard deviations (RSD, n=7) of oxygen and nitrogen were less than 9%, while the standard deviation (SD, n=7) of hydrogen was not higher than 0.000 5%.