偏振能量色散X射线荧光光谱法测定地质样品中18种元素  

Analysis of 18 elements in silicate geological samples by polarized energy dispersive X-ray fluorescence spectrometry

作　　者：王祎亚[1] 詹秀春[1] 刘以建[1] 樊兴涛[1] 周伟[1] 

机构地区：[1]国家地质实验测试中心,北京100037

出　　处：《分析试验室》2009年第9期90-94,共5页Chinese Journal of Analysis Laboratory

基　　金：国家地质实验测试中心基本科研业务费(200607CSJ12)项目资助

摘　　要：利用偏振能量色散X射线荧光光谱仪分析了硅酸盐基体样品。选取岩石、土壤、水系沉积物等国家一级标准物质，采用镶边粉末压片方法，选择Al2O3偏振靶、Mo、Co二级靶，在真空状态下对K、Ca、Ti、Cr、Mn、Fe、Ni、Cu、Zn、Ga、As、Rb、Sr、Y、Zr、Nb、Ba、Pb等18种元素进行选择激发和探测，所有元素的校正选用扩展的康普顿散射校正模型。各元素的检出限为0．4～10．9ug／g；除了As元素外，均达到了1：25万多目标地球化学调查规范的要求。根据60个地质调查多目标考核样品的分析结果，采用Rousseau（2001）所提出的相对不确定度计算方法，对所建立的方法进行了评估。Analysis for silicate geological samples, utilizing a polarized energy dispersive X-ray fluorescence spectrometer-spectro X-lab 2000 with a maximum tube power of 400 watts, was described. To obtain better signal/noise ratios, polarizers A12 03 and secondary targets Mo and Co were used for the excitation of different elements： K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Ga, As, Rb, Sr, Y, Zr, Nb, Ba, Pb, and the experiments were carried out in vacuum with powder samples including rocks, soils and stream sediments belonging to national reference materials which were pressed to polyethylene-backed pellets. Extended compton scattering model was used for matrix correction, which was suitable for trace and minor elements （K to U） in low Z matrix. Both precision and accuracy were good and the detection limits were 0.4- 10.9ug/g; the relative uncertainty of determination results for 18 elements were evaluated according to the Rousseau＇s model with 60 samples having different concentration distribution.

关 键 词：偏振能量色散x射线荧光光谱 地质样品 分析方法 不确定度 

分 类 号：O657.3[理学—分析化学]