Carbon speciation in airborne particulate matter with C (1s) NEXAFS spectroscopy.

Recent and current research activities on the chemical characterization of carbon in airborne carbonaceous particulate matter with near-edge X-ray absorption fine structure (NEXAFS) spectroscopy are reviewed. NEXAFS spectroscopy uses soft X-rays from synchrotron radiation facilities and allows for the bulk and surface speciation of particulates smaller than 2.5 micrometres (PM 2.5). This relatively novel technique is often superior to TEM-EELS and FTIR spectroscopy. In the extreme case, one single PM particle is sufficient for characterization. Liquids, extracts, solid core and surface functional groups can be quantified. Preliminary data on combustion derived PM such as diesel soot, wood smoke and tobacco smoke are compared with ambient samples.