| 摘要 |
The present method permits the qualitative and/or quantitative detection of suspended particles present in a gaseous carrier. To this end, the aerosol is heated, for example in a thermal diffusion separator. In the process, the suspended particles are brought to an elevated temperature, and substances are evaporated from the particle surface according to their volatility and bound to the wall of the thermal diffusion separator. This is followed by measuring the photoelectron emission from suspended particles which had earlier been flowing through the thermal diffusion separator. The dependence of the photoemission on the temperature of the thermal diffusion separator can be registered in a photothermogram and characterises the suspended particles. In an extension of the method, substances evaporated from the suspended particles, after enrichment on the wall of the thermal diffusion separator, are released again by heating and adsorbed on a scavenger aerosol of which the photoemission is then measured. The extended method enables quantitative determination of the suspended particle fractions associated with defined temperatures of the thermal diffusion separator. |
