X-Ray Fluorescence spectrometer (XRF)

Flat crystal spectrometer geometry

XRF Laboratory

X-Ray Fluorescence Sepectrometry (WDXRF) (Wavelength - despensive x-ray flourescence spectrometry is one of the most widely used and versatile of all instrumental analytical techniques. An XRF spectrometer uses primary radiation from an X-ray tube to excite secondary emission from a sample.
The radiation emerging from the sample includes the characteristic X-ray peaks of major and trace elements present in the sample. Dispersion of these secondary X-rays into a spectrum, usually by X-ray diffraction, allows identification of the elements present. The height of each characteristic X-ray peak relates to the concentration of the corresponding element in the sample, allowing quantitative analysis of samples for most elements in the concentration range 1 ppm to 100 %. To avoid particle size effects, rock samples should be ground as finely as possible, but the only way to eliminate particle size effects completely is to homogenise the sample by fusion. A mixture of lithiummetaborate and lithiumtetraborate is used for this purpose and fused with the sample in the ratio 1 part sample to 5 parts flux. Fused glass beads are only used in the determination of the major elements where the particle size effects are most dominant. Trace elements are determined on pressed powder samples made by mixing the powdered rock with a binder and pressing a pellet at high pressure. Operation is fully automatic and results are typically delivered within hours, minutes or even seconds.