Montag, 13. Januar 2014, 16:30 - 18:00 iCal

Aktuelle Themen in den Umweltgeowissenschaften III

Guest lecturer: Prof. Günter Allmaier, Institute of Chemical Technologies and Analytics, Vienna University of Technology

Title: Electrospray ionization combined with differential mobility analysis for the characterization of nanoparticles - from silver particles to intact viruses

Eberhard Clar-Saal (2B 204), Center for Earth Sciences
Althanstrasse 14, UZA II, , 1090 Wien

Seminar, Workshop, Kurs

For characterization of inorganic or organic nanoparticles as silver or SiO2 particles, protein complexes/aggregates, virus-like-particles (VLPs), vaccine particles or whole viruses, besides functional parameters usually methods as transmission electron microscopy (TEM), scanning electron microscopy (SEM) as well as atomic force microscopy (AFM) in the different modes, analytical ultracentrifugation, size exclusion chromatography (SEC), asymmetric flow field-flow fractionation (AF4), multiangle light scattering (MALS) or dynamic light scattering (DLS) are used. The use of electrospray ionization (ESI) for desorption and ionization for such kind of nanoparticles is a relative new development, i.e. to bring such kind of nano-objects as intact, ionic species into the gas-phase at atmospheric pressure. Now it is possible to generate ions with multiple charges as well as a single charge fixed on such nanoparticles. How this is done in the latter situation will be discussed in detail.

Here, we want to present one technique which opens up new avenues of analysis of the above mentioned nano-objects. First, the ESI/neutralizer ion source applied and afterwards the separation principle of the nano DMA (differential mobility analyzer) and its design will be presented. This part is combined with the description of the function of the universal detector CPC (condensation particle counter) and layout as well as limitations of this type of detector. This whole instrument (nano ES source with Po-210 charge reduction device, the nano DMA and the CPC) is called gas-phase electrophoretic mobility macromolecular analyzer (GEMMA, or sometimes also macroIMS or nano ES DMA), a separation device allowing the handling of particles from 2.5 to several hundred nm and measuring number concentrations.

The size and molecular mass of above mentioned nanoparticles can be obtained with an unsurpassed accuracy and completely without a vacuum system. Furthermore the device can be used for the determination of number concentrations as required by the EC recommendation of nanomaterials.




Andreas Gondikas
Universität Wien
0043 1 4277 53371