【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0.4~10.9μg/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。更多还原

【Abstract】 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 Al2O3 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 0.4～10.9 μg/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.更多还原