The SO2, COS, and H2S sulfur components are formed in the combustion engine during the combustion of fuel impurities in the cylinder. These are powerful catalyst poisons as well as the nuclei of particulate formation. The standard desulfation mechanism is a rich hydrocarbon load and hydrogen feed to the catalyst. This applies to nitrogen traps, particulate filters, and in general to all catalytic devices in exhaust gas treatment. To develop and fine-tune these types of strategies for desulfation, instrumentation is required that can accurately distinguish between SO2, COS and H2S while providing both sensitivity down to low ppm ranges and rapid response times.