The selection of exciting source both from the point of view of excitation efficiency and elimination of matrix effects using
incoherently scattered radiation from the analyzed sample is discussed. Samples of materials from the flotation process of
copper ore have been used and copper, iron and lead were the elements sought. For the excitation of fluorescence X-rays, sealed
radioisotopic sources of238Pu,241Am,244Cm,109Cd and a molybdenum X-ray tube were used. For X-ray analysis a Si(Li) spectrometer was applied. The processing of X-ray spectra
based on the application of the Gaussian peak representation gives results equivalent to the total peak area method. From
the intensities of fluorescence and scattered radiation, the contents of elements were calculated using empirical formulae
and the results were compared with those of the Heinrich-Rasberry method. A statistical analysis of the results has been carried
out and the criteria of optimal regression formula selection are given.