Sampling of particulate suspensions for morphological evaluation: a simple method for routine and quantitative use

A general method for obtaining representative samples of particulate suspensions for morphologic evaluation is presented. The key to the method is the orientation of a suitable substrate for sample collection normal to an applied centrifugal field. Precise orientation is achieved by floating the substrate on a dense water-immiscible fluid of low viscosity. Centrifugation may be performed in common angle-head centrifuge rotors. Two variations of the method are described which permit direct visualization or embedding of the particulate sample. Both variations are simple, can be performed routinely, and require only small amounts of material. They can also be performed simultaneously with centrifugation of the bulk samples.