Determination of oxidation states of aluminium, silicon and sulfur†

The lines of the emission spectra originating from vacancies in deep atomic shells change if the elements are in different oxidation states. These changes are shown in this paper, and also the influence that they may have on the calibration of wavelength-dispersive spectrometers and, in consequence, on quantitative analysis by XRF or EPMA. Also, these changes prove to be useful in identifying and, in some cases, quantifying phases in different oxidation states.