New method for density determination of nanoparticles using a CPS disc centrifuge™.

A model has been developed for the determination of the correct absolute size of nanoparticles using a disc centrifuge; the method does not require externally measured or literature derived particle densities. The principle of this method is the altered settling velocity of particles in fluids with different viscosities and/or densities, with the use of a linear regression analysis for the calculation of particle densities. This allows a fast particle density determination with at least two measurements using a disc centrifuge and a small subset of easily measurable parameters. Furthermore, correctness of the model is evaluated using viruses and nonbiological particles of known densities.