To determine the total sulfur content of a sample to be examined, it is known in the art first to convert the sulfur (sulfur compounds) of the sample either into sulfur dioxide by oxidation or hydrogen sulfide by reduction, i.e. into a compound that is relatively easy to analyze, and subsequently to determine the concentration of the compound by means of a suitable analysis method. For instance, the hydrogen sulfide can be separated from other components of the sample by gas chromatography and can then be readily determined by flame photometry (German Laid-Open Publication 37 35 599 A1). When the sulfur is oxidized, some portion of sulfur trioxide is also formed, in addition to the sulfur dioxide, as a function of the technical combustion conditions. This sulfur trioxide is unsuitable for quantitative determination due to its strong hygroscopic properties. Thus, it is desired to provide technical combustion conditions that cause the sulfur of the sample to be converted into sulfur dioxide to the largest extent possible. This can be achieved, for example, by using catalysts or reactors at temperatures in excess of 1000° C. Over time, however, the surface of the catalyst may become coated with solid particles, e.g., carbon, which are created and deposited during combustion of the sample. It is furthermore difficult to encapsulate the catalyst in such a way that its surface temperature permits use thereof in areas subject to explosion hazards.
USPTO Backgrounds
USPTO Backgrounds