便携式X射线荧光光谱仪现场测定地质样品中钛

On-site determination of titanium in geological samples by portable X-ray fluorescence spectrometer

使用便携式X射线荧光光谱仪对地质样品中钛进行了现场分析。由于仪器软件设计的不足,在含钡元素的样品中钛的检测结果偏高。实验对该结果产生的原因进行了讨论,认为钡元素的特征谱线叠加在钛上造成结果偏高,通过回归趋势分析及乘幂方式回归,提出了经验公式:y=0.487 8x0.911 6(x表示便携式X射线荧光光谱仪测试出钡的含量;y表示受钡影响的假象钛的含量),假象钛含量与样品中钡含量的散点图线性相关系数R2=0.999 3。据此经验公式计算出样品中受钡影响的假象钛含量,再用测试得到的总钛减去此假象钛即得实际的钛含量。实际验证34件矿山实际样品和4个国家标准物质,经校正后的测试结果与室内电感耦合等离子体原子发射光谱法测试结果或认定值基本吻合,两种方法测试结果的线性相关系数R2=0.936 2。方法检出限为0.021%,相对标准偏差(RSD)为1.7%。实验方法可在野外现场对钛元素实现半定量甚至定量分析,能够快速追踪异常,为快速圈定矿体提供了有效方法。

A portable X-ray fluorescence spectrometer was used for on-site analysis of titanium in geo- logical samples. Due to software design deficiency, the determination results of titanium in barium- containing samples were to the high side. The causes for these results were discussed. It was believed that the characteristic lines of barium overlapping with titanium led to the higher results. Through re- gression trend analysis and power regression, an empirical equation was proposed： y=0. 487 8x0.9116 （x stood for the barium content determined by X-ray fluorescence spectrometry~ y stood for the con- -- 35 --tent of false titanium content affected by barium）. of false titanium content and barium in the sample The linear correlation coefficient of scatter diagram was. R2 =0. 999 3. Based on this empirical equa- tion, the content of false titanium affected by barium in the sample was worked out. The actual con- tent of titanium was thus acquired through deducting the false titanium content by the total titanium content obtained by determination. Thirty-four mineral samples and four national certified reference materials were verified, whose results after correction were consistent with those of inductively cou- pled plasma atomic emission spectrometry or certified values. The linear correlation coefficient of the two methods results was R2 =0. 936 2. The detection limit was 0. 021%. The relative standard devia- tion （RSD） was 1.7%. The proposed ＇method could realize semi-quantitative or even quantitative on- site analysis of titanium in field. It can trace ahnormity rapidly, providing efficient method for fast de- lineation of mineral body.