Determination of sulfur and heavy metals in crude oil and petroleum products by energy-dispersive x-ray fluorescence spectrometry and fundamental parameter approach

Abstract

The combination of energy-dispersive x-ray fluorescence based on the secondary target excitation principle and of a quantification model based on the fundamental parameter approach provides a method for the determination of sulfur and heavy metals in crude oil and petroleum products. Samples are analyzed directly without any kind of sample preparation. For sulfur the analysis is performed under vacuum in an open cell arrangement. Further, a calibration procedure has been developed independent of both the sample matrix and instrument setting. This procedure and the quantification model have been applied to various certified reference materials and the results obtained proved to be accurate to within 2 to 5%. The precision (1 sigma) of the method is, however, better than 1.5% as long as the counting statistics are not the limiting factor.