Within this thesis, instruments and methods were developed for sampling devices and chemical analysis of PM 10 and PM 2.5. These two particle size fractions are European standards for air quality monitoring since 1999. A specially designed "ambient air sampling system" for the direct collection of PM 10, PM 2.5 and PM 1 on TXRF-sample carriers for subsequent analysis by Total-Reflection X-Ray Fluorescence Analysis (TXRF) was constructed and calibrated in the laboratory. Additionally, a PM 1-Inlet for a High-Volume-Sampler was developed. As a result, the determination of mass concentrations as well as important chemical constituents (anions and cations, elemental and organic carbon, heavy metals, polycyclic aromatic hydrocarbons) is possible for the fine particle fraction PM 1. The newly developed instruments were used together with commercially available PM 10- and PM 2.5-samplers for a field campaign at a traffic-related measurement site. Data analyses showed good results concerning quality assurance and dem onstrated the complementarities of the different sampling systems. A detailed characterization of the ambient aerosols was obtained and a first source apportionment could be conducted. However, the results also showed that for an efficient air pollution reduction strategy, particle size fractionated emission measurements are necessary as well. Therefore, a PM 10/PM 2.5 in-stack cascade impactor was designed and calibrated. During measurements at various industrial plants, the newly developed instrument showed good results concerning reproducibility and plausible data in comparison with mass concentrations obtained with the plane filter device for the determination of total suspended particulates (TSP). A chemical characterization similar to the ambient air particles was conducted with TXRF for some of the samples. The results showed that size fractionated particle sampling together with multielemental analyses give characteristic patterns ("fingerprints") of emissions. In a next step, the information can be used for source apportionment by fingerprintmodelling and the quantification of the contribution of different sources to ambient air particle concentrations.