Introduction
XRF (X-ray Fluorescence Spectrometry) is a chemical analysis tool commonly used for the quality control of raw materials and finished products in many industries including cement, mining and industrial minerals. The capabilities of XRF instrumentation have advanced significantly in the past decade in both sensitivity and stability such that they are no longer the most important source of error in an analysis. Sample preparation is now by far the most significant source of error in the analysis of materials by XRF. Viewed from this perspective, it is clear that high quality sample preparation techniques and practices are the key to achieving consistent and reliable analytical results.