Analysis of dissolved components from diesel soot particles

Since black carbon (BC) is a very fine particle of about 10-50 nm, there is a possibility that it invades deeply into lungs. In order to evaluate the impact of BC on human health, it is necessary to observe the detailed structure of BC with toxicology. A 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 imaging of the components of individual particle can be performed. However, since BC is very small, the detailed and interior structure of particles cannot be observed with only the FIB-TOF-SIMS. In this study, in order to evaluate the structure of BC, we combined the aerosol dialysis method and 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 oozed components, respectively.