Reliable Analysis of Very Low Levels of Sulphur in Petroleum Products - Bhaskar Bandyopadhyay & Dr. Kai Behrens

Sulphur in automotive fuels has been a source of toxic air pollutants like sulphur dioxide and sulphates. The international legislation enforces today very low residual sulphur concentrations in fuels, like the actual limit of 30 ppm for diesel in the US. The EU directive 2003/17/EC regulates the maximum allowed level in the European Union to 10 ppm. Future regulations may drive these limits down even further. Wavelength-dispersive X-ray fluorescence (WDXRF) analysis is today the method of choice for accurately and precisely analyzing low sulphur concentrations in petroleum products. WDXRF instrumentation is easily integrated into industrial environments such as refineries and laboratories due to its simple sample preparation, reliability, ease-of-use and accurate analytical results.

The S8 TIGER 1 K of Bruker AXS brings additional advantages for the analysis of low sulphur in petroleum products and is easily satisfying the requirements of ASTM D 2622-08. This article will outline the analytical performance of the S8 TIGER and describe the specific benefits for this analytical task.

Instrumentation
The S8 TIGER 1 K is the perfect solution for performing elemental analysis for the hydrocarbon processing industry. Traces of sulphur can be analysed with very low detection limits and best precision due to the optimised beam path. High sensitivity for sulphur is achieved with the close coupling between X-ray tube and sample and the curved germanium analyser crystal. Without the need for an additional external cooling device and no need of compressed air the installation and reliable operation is guaranteed for the S8 TIGER 1K.

The S8 TIGER 1 K is optimised for highest instrument uptime, lowest cost of ownership and ultimate reliability. The unique SampleCareTM feature of the S8 TIGER 1 K outperforms other conventional WDXRF due to its complete protection of the spectrometer chamber and its components in case of sample spillage. The unique vacuum seal separates the sample and spectrometer chamber and ensures complete reliability for petroleum users. It locks out fumes from diesel and gasoline which otherwise will enter the spectrometer chamber damaging crystals, motors and detectors. In addition it significantly reduces the helium consumption and therefore the cost of operation, because helium flushing is only required for the small sample chamber, while the spectrometer chamber remains always in vacuum.