X-ray fluorescence (XRF) spectroscopy is a powerful method to investigate the elemental chemical state in unknown
compounds and the electronic structure of materials. It is well known that the X-ray spectra are sensitive to the chemical states of
the emitting atoms and are of great use for studying the atomic and electronic structure in materials. It is demonstrated that the
chemical state of relevant element in an unknown material can be analyzed by the use of the chemical shift.