Rigaku Corporation has announced the publication of a new application note for the determination of ultra-low sulfur (ULS) levels in automotive fuels using wavelength dispersive X-ray fluorescence (WDXRF) spectrometry.
Rigaku Application Note #XRF 5053 describes the capabilities of the new Rigaku Micro-Z ULS benchtop WDXRF sulfur (S) analyzer for the quantitative analysis of low concentration sulfur in automotive fuel, in accordance with the American Society for Testing and Materials method ASTM D2622-10, which covers the Standard Test Method for Sulfur in Petroleum Products.
The application note details sample preparation, method calibration and repeatability.
Recent developments in ultra-low sulfur fuel have improved fuel efficiency and resulted in cleaner emissions. Sulfur content in fuels, however, is strictly controlled as it is a significant contributor to atmospheric pollution in petroleum-based fuels.
Globally, the allowable sulfur limit in fuel oils has been decreased in many regions to as little as 10 ppm. X-ray fluorescence (XRF) spectrometry is the quintessential analysis tool for compliance verification and is used at distribution terminals and refineries, as well as in testing laboratories.
As described in the report, analysis was performed using the Micro-Z ULS WDXRF analyzer, a benchtop spectrometer with fixed optics optimized for sulfur analysis.
In recent years, there has been an increasing need for an instrument that does not require the use of helium gas for instances when acquisition or delivery of helium to the analysis site is difficult.
The atmosphere in the optics path of the Micro-Z ULS spectrometer is a vacuum, so helium gas is not required.
For the described method, “number 2 diesel fuel” standards and isooctane-based standards were used for calibration of diesel fuel and gasoline respectively. Repeatability tests were carried out using a representative sample for each material.
The test results detailed in the report demonstrate that low concentration sulfur in petroleum-based fuel can be routinely analyzed with high accuracy and precision on the Micro-Z ULS benchtop WDXRF spectrometer, meeting the requirements of ASTM D2622-10, which has become stricter in the recent versions of ASTM D2622.