Elemental chemical speciation by measuring x-ray energy shifts has been carried out by various authors in the past, using tube excitation and wavelength detection. Among the most intense determined shifts are those of vanadium compounds; further, vanadium speciation determination seems to be even more important than total element analysis. In this work, the possibility of vanadium compound speciation by measuring K x-ray line energy shifts was studied by using radioactive source excitation and detection by an energy-dispersive Si(Li) detector of moderate resolution. The effect of the fitting parameters to the results was examined for the K–L2,3 and K–M2,3 lines, and the results are compared with previous data obtained by wavelength-dispersive x-ray fluorescence.