Chemical characterisation of micro- and nanoparticles by ICP spectrometry

• Applicant: Dr. Carmen Cecilia Garcia Perez
• Subject Area: Analytical Chemistry
• Term: from 2007 to 2009
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 38294298

The implementation of a reliable quantitative method for rapid on-line characterization (mass and elemental composition) of airborne micro- and nanoparticles is investigated. Elemental characterization is accomplished by using inductively coupled plasma optical emission or mass spectrometry (ICP-OES/MS). Applying well characterized particles of known composition for calibration, the measurement of the correlation between the monitored signals (either mass or emission) and particle mass is the main goal of the analytical method. The elaborateness of the method requires careful investigation and understanding of (i) particle atomization and its impact on the local plasma parameters, (ii) the atomic diffusion processes in the ICP, and (iii), for mass spectroscopic detection, the local ionization of the element atoms. These processes are expected to be dependent on particle size, composition and morphology on the one hand, and the trajectories and transient times of the particles through the ICP on the other. For these studies, particles of reproducible mass and composition are generated from desolvated monodisperse droplets of known standard solutions. In some cases, commercially available nanoparticles of pure metals or metal compounds will be used. Independent techniques, such as electron micro probe or total reflection X-ray fluorescence, are also applied for characterization of the particles.The proposed investigations will also give deeper insight in the atomization/ionization processes and in mass load effects important for LA-ICP-MS analysis and eventually may help to improve the accuracy of this widely used technique.

• DFG Programme: Research Grants