X-ray fluorescence raw intensities vs. concentration data for multivariate classification of hungarian coal

A set of coal samples was examined by routine methods of coal analysis (density, calorific value, sulfur content, etc.) and by trace element determinations on the coal ash. Both data sets gave satisfactory clustering of samples from similar geological zones. X-ray fluorescence spectra were evaluated in order to identify the significant data-reduction steps in the sequence raw spectra/net intensities/trace element concentrations that is commonly used in x-ray spectrometry. The deconvolution yielding net intensities from spectra was identified as the most significant step. This was explained by the decorrelation effect of geochemically dissimilar elements.