Determination of the Total Sulphur Content in Gas Oils with a Flame Photometric Detector

During a study of catalytic hydrodesulphurization of gas oils’ a method was needed not only for the determination of the distribution of sulphur compounds, but also, more importantly, for the determination of total suIphur content. Methods have been published for the determination of the distribution of sulpbur compounds in gas oils using gas chromatography (GC) with a coulometric detector’>3. The flame photometric detector (FPD) has proved its usefulness for the analysis of sulphur compounds. The response of the FPD for nanogram amounts of sulphur is comparabIe with that of the microcoulometric detector”. The dual-flame concept was introduced to improve the FPD performano9. The work of Rupprecht and Phillips6 is of particular interest, since the system was used not only as a GC detector but also for the continuous monitoring of the odorant suiphur content in hydrocarbon gases and the determination of sulphur content in volatile liquids. Difficult operation and somewhat poor reproducibility apparently prohibited a more widespread use. These problems seem to be greatly reduced in a more’recent design’. In this paper a simple method is described for the quantitative determination of the total sulphur content in oil fractions, using a gas chromatograph with an empty glass column and a dual-flame FPD. The method was extended to the determination of the total (volatile) sulphur content of aqueous solutions. This was applied to a scrubber for gasifier effluents.