Sulfur chemical state analysis of diesel emissions of vehicles using X-ray absorption

Soft X-ray absorption spectra of sulfur K edge were measured for diesel exhaust particles from three different vehicles. The X-ray spectra were measured using a synchrotron radiation beamline. The spectra were measured by surface sensitive total electron yield method and bulk sensitive X-ray fluorescence yield method. One vehicle concentrated the S2− on the surface of the emission particles; the others did not concentrate S2−. This type of chemical state analysis method is useful for the process analysis such as diesel emissions.