Rigaku Americas Corporation has announced the publication of a new application report on sulfur analysis in petroleum products using wavelength dispersive X-ray fluorescence (WDXRF) spectrometry.
Application Note #5012 describes the performance of the Rigaku ZXS Primus WDXRF spectrometer and presents the analysis of sulfur, with complete information regarding sample preparation, method calibration and repeatability.
The report adheres to the American Society for Testing and Materials Method ASTM D2622-10, Standard Test Method for Sulfur in Petroleum Products by Wavelength Dispersive X-ray Fluorescence Spectrometry.
Crude oil typically contains sulfur in concentration from 0.5 to 5.0 mass%. Sulfur in petroleum-based fuels contributes to atmospheric pollution and is strictly regulated.
Sulfur also causes damage to facilities, such as catalysts in refinery processes; therefore, control of the level of sulfur in refinery intermediates and final products is critical.
Control of sulfur content is also very important in the petroleum industry from the standpoints of both environmental impact and production cost.
Among the benefits of using X-ray fluorescence (XRF) spectrometry for quantitative analysis of sulfur in petroleum products is its simple sample preparation requirements.
The ZSX Primus, a tube-below sequential WDXRF spectrometer, is optimized for the routine analyses that today’s petroleum laboratories need to perform.
For the published method, measurements were performed on the ZSX Primus with a 3 kW X-ray tube operating at 30 kV and 80 mA using a Ge analyzing crystal and the S4 slit, included in the standard configuration.
The beryllium primary beam filter, inserted between the sample and the X-ray tube, protects the X-ray tube window against damage from samples leaking during measurement.
The counting time for low sulfur concentration was 200 seconds for peak and 100 seconds for background; for high sulfur concentration, 20 seconds and 10 seconds respectively.
The results detailed in the report show that sulfur in petroleum products can be routinely analyzed in both low and high concentration ranges with great accuracy, sensitivity and repeatability using the ZXS Primus WDXRF spectrometer, meeting the requirements of ASTM D2622-10, which has become stricter in the recent versions of ASTM D2622.