Particle Sizing

Many natural and manufactured products involve particulate materials either in their final state or at some stage in their production. Particle size and particle size distribution are, therefore, often critically important parameters.

The Importance of Particle Sizing

image of particle sizing At the simplest level, information on particle size can help maintain a more consistent product, enhancing end-user value and profitability. At a more complex level, careful control of particle size can reduce the need for in-process modifications and reworking, so making products more competitive. The presence of protein aggregates can ruin a pharmaceutical preparation.

Dynamic Light Scattering (DLS) provides a fast, simple method for submicron and nanoparticle sizing. In this technique, random intensity fluctuations arising from the Brownian motion of particles and proteins are analyzed by autocorrelation to give either a simple mean size and polydispersity (distribution width), or more complete distribution data even for multimodal distributions.

Sedimentation/Centrifugation provides high resolution and accuracy over a wide size range from nanometers to microns. It is based on the fractionation of particles according to Stokes’ Law, and particle density is the only special information required. Measurement times are typically in the range of five to thirty minutes, depending upon the breadth of the distribution.