Feasibility of high-resolution continuum source molecular absorption spectrometry in flame and furnace for sulphur determination in petroleum products

Title Feasibility of high-resolution continuum source molecular absorption spectrometry in flame and furnace for sulphur determination in petroleum products
Author: Kowalewska, Zofia
Spectrochimica Acta Part B: Atomic Spectroscopy, 2011
2011
http://www.sciencedirect.com/science/article/pii/S0584854711001066
More details: For the first time, high-resolution molecular absorption spectrometry with a high-intensity xenon lamp as radiation source has been applied for the determination of sulphur in crude oil and petroleum products. The samples were analysed as xylene solutions using vaporisation in acetylene-air flame or in an electrothermally heated graphite furnace. The sensitive rotational lines of the \{CS\} molecule, belonging to the ?��$\nu$\&\#xa0;\#xa0;0 vibrational sequence within the electronic transition X1?��+\&\#xa0;?��\&\#xa0;A1?�, were applied. For graphite furnace molecular absorption spectrometry, the Pd\&\#xa0;+\&\#xa0;Mg organic modifier was selected. Strong interactions with Pd atoms enable easier decomposition of sulphur-containing compounds, likely through the temporal formation of PdxSy molecules. At the 258.056\&\#xa0;nm line, with the wavelength range covering central pixel ??\&\#xa0;5 pixels and with application of interactive background correction, the detection limit was 14\&\#xa0;ng in graphite furnace molecular absorption spectrometry and 18\&\#xa0;mg\&\#xa0;kg?��1 in flame molecular absorption spectrometry. Meanwhile, application of 2-points background correction found a characteristic mass of 12\&\#xa0;ng in graphite furnace molecular absorption spectrometry and a characteristic concentration of 104\&\#xa0;mg\&\#xa0;kg?��1 in flame molecular absorption spectrometry. The range of application of the proposed methods turned out to be significantly limited by the properties of the sulphur compounds of interest. In the case of volatile sulphur compounds, which can be present in light petroleum products, severe difficulties were encountered. On the contrary, heavy oils and residues from distillation as well as crude oil could be analysed using both flame and graphite furnace vaporisation. The good accuracy of the proposed methods for these samples was confirmed by their mutual consistency and the results from analysis of reference samples (certified reference materials and home reference materials with sulphur content determined by X-ray fluorescence spectrometry). Continuum source,Molecular absorption spectrometry,Palladium modifier,Petroleum,Sulphur determination

Thematic Issue: European Symposium on Atomic Spectrometry (ESAS 2010)

No comments:

Post a Comment