布鲁克Bruker---X射线荧光光谱分析备样技术 分析层的厚度：无限厚 X-ray tube to soller slit (collimator) analysed layer (saturation depth) Sam布鲁克Bruker---X射线荧光光谱分析备样技术 分析层的厚度：无限厚 X-ray tube to soller slit (collimator) analysed layer (saturation depth) Sample 分析层的厚度：无限厚 Sample B KA1 (0,18 keV) Sn LA1 (3,4 keV) Cr KA1 (5,4 keV) Sn KA1 (25,2 keV) tube to soller slit Is your sample homogeneous ? Analysed layer on the sample surface no excitation within the inner (upper) part of the sample the lower parts (layers) of the sample can be excited (by short wavelengths) but emmitted radiation will be absorbed within the sample fluorescence radiation to be measured comes from a layer near the sample (specimen) surface 分析层的厚度：无限厚 0,01 mm = 10 nm = 100 A atom radius: 0,5 - 3 A tube 分析层的厚度：对于轻基体（如液体） Light matrix 颗粒效应: 不均匀的颗粒样品 CaCO3 SiO2 压片样品 松散样品 颗粒效应:不均匀的颗粒样品 分析层 !! analysed layer 颗粒效应:不均匀的颗粒样品 松散样品 Na to U absorption in foil He flushing required ? for qualitative and semiquantitative analysis for quantitative analysis in special cases only（一般是压不成片的时候） 压片制样 press as pure pellet on a support of boric acid in steel rings in aluminium cups add binder if necessary wax ( C and H) boric acid ( B, H and O) 压片制样的精密度 熔融制样 熔融设备 马弗炉 燃气炉 inductively heated 熔剂 lithiumtetraborate Li2B4O7 lithiummetaborate LiBO2 mixtures of Li2B4O7 and LiBO2 白金坩埚 (crucibles and moulds) Analysis of Raw Meal Samples Pressed pellets versus fused beads Samples six certified reference materials (Holderbank) Two different preparation methods fused beads g of material g of flux pressed pellets with 20% of wax Analysis of Raw Meal Samples Pressed pellets versus fused beads 压片制样和熔融制样的分析结果的比较 压片制样和熔融制样的分析结果的比较 The comparison of the two different preparation methods clearly shows: sensitivities and LLD´s are better for pressed pellets the accuracy is much better for fused beads up to a factor of 10 for SiO2 液体样品 水,油, 溶液,泥浆, ... 尽量不要分析对仪器有腐蚀或
