Читать книгу X-Ray Fluorescence Spectroscopy for Laboratory Applications - Michael Haschke, Jörg Flock - Страница 25

Analytical tasks for element analyses can vary broadly. They can be

 a simple determination of the elements present in the laboratory sample (qualitative analysis);

 a monitoring of the content of one or more elements with respect to a predetermined threshold value (semiquantitative analysis);

 a comparison of the measured intensities of one or several elements with those of reference samples for identifying a material class (positive material identification – PMI);

 the quantitative determination of the mass fractions of some or all elements in the sample material with a predetermined uncertainty level as an overview analysis, as well as for an accurate or even highly accurate analysis (quantitative analysis);

 the characterization of layer systems on the sample with respect to layer thickness and layer composition, again with different accuracy requirements;

 the determination of element distributions in inhomogeneous samples.

Starting from these very different objectives, the individual steps for the analytical method are to be defined, such as the selection of

 the equipment to be used for the measurement

 the reference samples to be used to calibrate the method

 the selection of appropriate measuring conditions as well as

 the procedures for data processing and evaluation.