Analysis of dissolved components from diesel soot particles

Since diesel soot particles (black carbon, BC) is a very fine particle of about 10 to 50 nm, there is a possibility that it invades deep into human lungs. In order to evaluate the impact of BC on human health, it is necessary to observe the detailed structure of BC along with toxicology. Focused ion beam time-of-flight secondary ion mass spectrometer (FIB-TOF-SIMS) developed by the authors, has a high spatial resolution and low detection limit, and the components imaging of individual particle can be analyzed with many kinds of aerosol. However, since BC is very small, the detailed structure of particles cannot be observed directly with the FIB-TOF-SIMS. In this study, in order to evaluate the structure of BC, we combined a new aerosol dialysis method and the FIB-TOF-SIMS. In this method, even if the lateral resolution is insufficient, the structure of BC can be visualized with separating the particles and surface adhering components, respectively.