直流辉光放电质谱法测定海绵钛中杂质元素

将海绵钛样品压制成片,在缺乏合适标样情况下可以用多种金属得出的典型RSFX值对测定结果进行校正,建立了直流辉光放电质谱法(GD-MS)测定海绵钛中Be、B、C、N、O、Na、Mg、Al、Si、P、S、Cl、K、Ca、V、Cr、Mn、Fe、Co、Ni、Cu、Zn、Ga、As、Y、Zr、Nb、Mo、Sn、Sb、Pb、Bi等32个痕量杂质元素的分析方法。考察了放电参数对分析信号灵敏度和稳定性的影响,优化后的放电参数如下:辉光放电电流为38 mA,放电电压为650 V,放电气体流量为450 mL/min,预溅射时间为30 min。通过选择合适的同位素,在高分辨(HR,分辨率R=10 000)质谱模式下测定K,在中分辨(MR,R=4 000)模式下测定其他元素可消除质谱干扰。将实验方法应用于海绵钛实际样品中32个杂质元素的测定,结果的相对标准偏差(RSD,n= 10)为3.3%～30%,主要金属杂质元素含量的测定结果与采用电感耦合等离子体质谱法(ICP-MS)的分析结果基本一致。采用实验方法分析商用0级海绵钛样品(样品1)和1级海绵钛样品(样品2),所得结果与国家标准(GB/T 2524—2010)中对两种等级海绵钛的含量要求一致。其中Fe、Si、Cl、C、N、O、Mn、Mg的测定结果与采用国家标准GB/T 4698—2011的分析结果相吻合。

Determination of impurity elements in titanium sponge by direct current glow discharge mass spectrometry

The titanium sponge sample was pressed for sample preparation. Due to the lack of proper standard samples, the determination results were corrected with typical RSFX value obtained by several metals. The analysis method of 32 trace impurity elements (including Be, B, C, N, O, Na, Mg, Al, Si, P, S, Cl, K, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Y, Zr, Nb, Mo, Sn, Sb, Pb and Bi) in titanium sponge by direct current glow discharge mass spectrometry (GD-MS) was established. The influence of discharge parameters on sensitivity and stability of analytical signals was investigated. The optimized discharge parameters were listed as follows: the glow discharge current was 38 mA, the discharge voltage was 650 V, the discharge gas flow rate was 450 mL/min, and the pre-sputtering time was 30 min. The content of K was determined under high resolution (HR, R=10 000) mass spectrometry mode by selecting the proper isotopes. Other elements were determined under moderate resolution (MR, R=4 000) mode to eliminate the mass spectrometry interference. The experimental method was applied to the determination of 32 impurity elements in actual titanium sponge sample. The relative standard deviations (RSD, n=10) were between 3.3% and 30%. The determination results of main metal impurity elements were consistent with those obtained by inductively coupled plasma mass spectrometry (ICP-MS). The proposed method was used to analyze commercial grade-0 (Sample 1) and grade-1 (Sample 2) titanium sponge samples. The found results were consistent with the content requirements in national standard (GB/T 2524—2010). Therein, the analytical results of Fe、Si, Cl, C, N, O, Mn and Mg were consistent with those obtained by national standard (GB/T 4698—2011).