Fourteen Peaks?! Particle Size Analysis of a Mixed Sample of Polystyrene Latex Standards

Certified National Institute of Standards and Technology (NIST) traceable polystyrene latex (PSL) size standards made by Thermo Fisher Scientific Inc. (TFS) were used to evaluate the resolution of the centrifugal sedimentation method. Mean diameters of the PSL standards have been calibrated with microscopy methods. Size distribution and uniformity were measured with electrical resistance analysis or optical microscopy.  Fig. 1 shows the photograph of PSL particles. They have excellent roundness with a full particle size distribution. A mixed sample of fourteen sizes of monodispersed PSL was used to evaluate the resolution and quantitative capability of the centrifugal sedimentation method.