Preparative particle separation by continuous SPLITT fractionation

Split-flow thin-cell fractionation (SF) was one of Cal Gidding's later inventions in the field of separation science. In the mid 1980's, he began work on this technique, which is in many ways similar to field-flow fractionation (FFF), but which ultimately offers yet another dimension to his list of credits: preparative separations. SF is applicable to particles and macromolecules and offers advantages similar to FFF techniques in separation speed, resolution, breadth in applicable size range, gentleness, and flexibility of separation conditions. However, SF singularly offers the possibility for continuous operation and thus preparative scale throughputs. After more than 10 years of developmental work by the Giddings research group, SF has now become a reliable high-resolution technique for separation of particles in the micron size range. In this article, the factors influencing resolution, throughput, and scale-up of SF are considered and discussed. Preparative scale separation using gravitational SF is shown by the separation of silica and synthetic diamond particles. © 1997 John Wiley & Sons, Inc. J Micro Sep9: 261–273, 1997