X-Ray fluorescence is one of the most versatile methods to determine elements in a sample. The material is exposed to x-rays that cause each element to emit its own unique fluorescent x-ray. The subsequent analysis of the results is based on comparisons to standard samples with given chemical composition.
Sample preparation of materials has become more and more important because of the rapid development and improvement of both software and XRF-devices during the past few years that shifts the detection limit for trace analyses. It is crucial to be aware of the particle size, which needs to be between 20 μm and 60 μm, as it can strongly influence the results given that the intensity of fluorescent x-radiation decreases with increasing particle sizes.
Furthermore the sample needs to be both representative and homogeneous in order to eliminate factors, such as unevenness of the surface, that can also influence the results. A decisive and often underestimated factor in the process of sample preparation is the use of sample dividing to guarantee that the sub-sample accurately represents the original sample particularly in cases where it is not possible to grind the whole sample to the necessary fineness. (...)