Determination of the phosphorus and sulphur content in edible oils and fats by wavelength‐dispersive x‐ray fluorescence spectrometry

A method was developed for the determination of phosphorus and sulphur in edible oils and fats by wavelength-dispersive x-ray fluorescence (WDXRF) spectrometry. The samples were measured in disposable liquid cells after solidification with 15% stearic acid to obtain a stable measurement. The WDXRF method was compared for phosphorus with graphite furnace atomic absorption spectrometry and for sulphur with an oxygen combustion method. The detection limit was 2 mg kg-1 for both phosphorus and sulphur and the long-term precisions for phosphorus and sulphur were 3% and 5% (RSD), respectively, at 40–50 mg kg-1. The WDXRF method is also suitable for the determination of phosphorus in lecithins. © 1998 John Wiley & Sons, Ltd.