Crude oil contains sulfur in concentration from 0.5 mass% to 5.0 mass% typically, and control of the level of sulfur in refinery intermediates and final products is critical in a refinery. Sulfur in petroleum-based fuels causes atmospheric pollution; therefore, sulfur content in fuels, especially in automobile fuels, is strictly controlled. Sulfur also causes damage to facilities such as catalysts in refinery processes. Therefore, control of sulfur content is very important in the petroleum industry from the standpoints of both environment and production cost.

X-ray fluorescence (XRF) spectrometry has been used for quantitative analysis of sulfur in petroleum products, owing to simple sample preparation. In XRF analysis of oil, samples are simply poured into liquid cells and any complicated treatments such as chemical decomposition or dilution are not required. In addition, concentration of total sulfur is obtained in XRF analysis.

This application note demonstrates quantitative analysis of sulfur in petroleum products according to ASTM D2622-16 on Rigaku ZSX Primus IVi, a wavelength dispersive X-ray fluorescence (WDXRF) spectrometer.