Das Projekt "Aerosolprobenahme fuer off-line Partikelanalyse" wird vom Umweltbundesamt gefördert und von Universität Duisburg, Fachbereich 9 Elektrotechnik, Fachgebiet Prozess- und Aerosolmesstechnik durchgeführt. Due messing in-situ and on-line particle analysis systems to determine size, shape and chemical composition of ambient particles, the particles must be depsited on an suitable sample support and examined by an off-line analysis. To analyse those partieles, highly sensitive analytical instruments have to be used. Analtic instruments like scanning electron microscopy and energy dispersive x-ray (SEM and EDX), total reflection x-ray fluorescence or scanning atomic force microscopy (SAFM) have low detection limits. All analytic techniques have in common, that they need a representative, homogeneous particle size distribution with sufficient mass on a chemical resistant sample support with a flat surface. We developed an electrostatic precipitator (ESP) to deposit unipolarly charged submicron particles homogenously on chemical resistant and analytic sutiable samples carriers. This particle sampling technique for direct physical and chemical analysis avoids preparation and consequently contamination. The ESP was used in a new developed sampling train consisting of a dilution probe, an impactor, a corona charger and the ESP as back-up filter (dixkens 1995). A special dilution probe was designed in order to reduce coagulation of a highly concentrated aerosol and the penetration of the sampling device was checked. The calculated and measured particle penetration of the dilution probe indicates that the aerosol can be diluted without changing the particle size distribution. The flow within the probe is sucked through an impactor followed by a corona charger and the ESP. The micron particles with diameters above 1 my m are collected with an impactor on a sample support (e.g. nuclepore filter). The not collected sumicron particles are unipolarly charged in a corona charger and deposited in the designedESP on a sample support (e.g. quartz-glass) by an electrostatic filed. Experiments shows that the particles are collected homogeneously on the quartz-glass sample support and the designedsampling train is a feasible tool to collect particles for off-line particle analysis (Fissan and Dixkens 1996). Due to the chargng efficiency of the corona charger it is not possible to charge nanometer particles below 50 nm up to 100 percent. For example the charging efficiency of 10 nm particles is less than 10 percent. Therefore the particle sampling efficiency of the ESP is also less. In order to sample especially nanoparticles below 50 nm we developed a Nano-ESP. The total sampling efficiency was improved byusing an additional thermophoretic force and by increasing the particle deposition due to diffusion. Experiments show that it is possible to collect nanometer particles on a sample support (e.g. TEM-grid) with this new Nano-ESP.