X-Ray Fluorescence Analysis (XRF)
X-Ray Fluorescence Analysis is the principal method for all bulk chemical analyses of rocks at the Helmholtz Institute Freiberg for Resource Technology.
|XRF spectrometer AxiosmAX from PANalytical|
|Photo: HZDR/ Robert Möckel|
- XRF spectrometer type: AxiosmAX from PANalytical
X-ray source: Rh
- Fast, quantitative measurement of major, minor and trace elements
- Detection limits from 10 to 200ppm (element and matrix dependent)
- Samples need to be ground (< 63µm, sample preparation can be carried out at our institute)
- Quantities: approximately 2g for the major element analysis (loss on ignition has to be determined) and approximately 10g for trace element analysis
- Sample composition should be roughly known to avoid preparation errors (fused vs. pressed tablet)
- Matrix dependent method
- Calibration for silica rocks is available
- Another measuring strategy, which is partly based on the fundamental parameter approach, can be used for very complex matrices
- Uhlig, S.; Möckel, R.; Pleßow, A.
"Quantitative analysis of sulfides and sulfates by WD-XRF: Capability and constraints", X-Ray Spectrometry (2016)
How does it work?
Secondary X-rays are generated by bombarding a flat sample surface with primary high-energy X-ray. The secondary X-rays show the specific energy pattern of all chemical elements present in the sample. They are either determined by the energy itself or by the respective wavelength. Our PANalytical AxiosmAX spectrometer is a wavelength discriminating device, in which certain wavelengths are separated by diffracting crystals (see picture) and associated to a certain element. The concentration of the element of interest can be recalculated from a calibration.
|X-Ray fluorescence analysis principle|
|Photo: Brucker AXS S8 Tiger Information Brochure|