Performance of Larger Diameter Columns for High Speed Liquid-Solid Chromatography

Larger internal diameter (10.9 mm) liquid-solid chromatographic (LSC) columns packed with Porasil® A are shown to be more efficient than the normally used narrow-bore columns packed with this same support. The observed improvements in column performance are the result of the same “infinite-diameter” effects previously shown to occur in liquid-liquid chromatographic columns packed with a controlled surface porosity support. Several chromatographic parameters which have implications for the optimization of preparative liquid chromatography are discussed. It appears that the use of large sample volumes and dilute sample solutions give rise to higher column efficiency for a given weight of solute. In addition, for maximum sample throughput, columns should be operated at the highest carrier velocity which will permit adequate resolution of the desired sample components. Two examples of large-scale LSC separations are presented.