Conference Report: International Workshop Dispersion
Analysis and Materials Testing, September 2016, Berlin, Germany
by Dr.-Ing. Hildegard Lyko, free-lanced journalist
Extract from the full report:
Particle characterization
Analytical centrifugation with measuring time- and position resolved light transmission delivers extinction weighted size distributions of the particles’ Stokes diameters. A cooperation project of TU Dresden, LUM and Doshisha University in Kyoto, Japan (Prof. Yasushige Mori) aimed at developing a transformation method from extinction weighted to volume or number weighted size distributions, which does not refer to a model that describes the optical behaviour of particles (e.g. Mie theory). As Dr. Frank Babick, TU Dresden, pointed out, this transformation can successfully be made by applying multi-wavelength analysis of photo-centrifugation data. Promising results were obtained with mineral materials SiO2, Al2O3, TiO2 as well as with Au. However, there seem to be materials, with which this transformation method without knowing the refractive index is not applicable..
Julia Groß, Boehringer Ingelheim Pharma GmbH reported about a study to evaluate the STEP technology (LUMiSizer) for protein particle detection and protein aggregation studies, especially for the analysis of mAB solutions and highly concentrated liquid formulations (HCLFs). The main challenge for analysing these protein formulations is given by their low turbidity. It was shown that the LUMiSizer could successfully be applied, if the turbidity of the protein solution had previously been increased by mechanical or thermal stress on the proteins.
Analytical centrifugation has also proved a suitable tool to measure size distributions of nanoparticle formulations. Thus this measurement principle is currently evaluated in the frame of the EU project NanoDefine, which was presented by Christian Ullmann from TU Dresden. According to the definition given by the European Commission in 2011, nanomaterial is a material with more than 50 % of the particles in the number size distribution having their smallest dimension below 100 nm. Within NanoDefine the accuracy and reproducibility of measuring “real world materials” (not spherical, some of them are borderline materials with dimensions near 100 nm) with different analytical centrifuges were compared.
The next International Conference and Workshop Dispersion Analysis & Materials Testing will take place in Berlin, Germany, from 29-30 January 2018.
