This method is for determining the total chloride content of fresh, regenerated, and spent alumina supported catalysts by wavelength dispersive x-ray fluorescence (WD-XRF) spectroscopy. The range of quantitation is from 0.01 to 3 mass-% and applies to samples containing less than 10 mass-% water and other volatiles as determined by loss on ignition (LOI) measurement at 900 °,C. The upper concentration limit of the method can be extended if appropriate standard and reference materials can be obtained. See Notes for matrix-effect and other interferences.