Wu Shu, Wang Quanhua, Zhu Xi, Luo Xiaoyun, Tang Yong
The extensive application of high-purity titanium in high-end fields such as aerospace and medical care imposes strict requirements on its purity.However,the traditional detection methods suffer from low efficiency and the risk of introducing foreign impurities,which cannot meet the current analytical demands.Accordingly,an analytical method based on glow discharge mass spectrometry (GDMS) was established for the determination of 23 impurity elements (Li,B,Na,Mg,Al,Si,Cl,K,Ca,V,Cr,Mn,Fe,Ni,Co,Cu,Zn,Zr,Mo,Ag,Sn,W,Pb) in high-purity titanium.Through systematic experiments,the optimal detection isotopes and instrument working parameters (i.e.,discharge current of 2.0 mA,discharge voltage of 980 V,and pre-sputtering time of 20 min) for each element were determined.High-purity titanium sample was used for validation,and it was found that the relative standard deviations (RSD,n=6) of determination results for tested elements were all less than 30% with good repeatability.Except for Na,V,and Zn,the detection results of the other elements were basically consistent with those obtained by inductively coupled plasma mass spectrometry (ICP-MS).Due to the restriction of matrix-matched certified reference materials,the matrix matching correction of relative sensitivity factors (RSF) was only conducted for Al,Sn,Mo,Si,Ni,Cr,Mn,Fe and Cu.After correction,the absolute relative biases of determination results of these elements compared to ICP-MS method were controlled within 30%.The limits of detection of the proposed method reached the level of 10 ng/g or even 1 ng/g for most elements,which could meet the detection requirements of trace impurity elements in 4 N-grade (99.99% purity) and higher-grade high-purity titanium.
