Determination of particle size distribution by gravitational field-flow fractionation: Dimensional characterization of silica particles

Summary Gravitational field-flow fractionation (GFFF) is the simplest and cheapest of field-flow fractionation (FFF) techniques, although it is still at an early development stage. The application of GFFF to the determination of particle size distribution (PSD) of silica particles used as chromatographic supports is described. The accuracy of the method is evaluated by comparing PSDs obtained by GFFF with those obtained by laser diffraction, a non-separative technique widely applied to particle characterization. It is ultimately demonstrated that a low-cost GFFF channel can simply replace the column of a standard HPLC system, allowing laboratories that are not specialized in size analysis to perform accurate PSD studies with standard HPLC expertise.