Investigation of the Influence of Particle Size on the Productivity of Preparative HPLC Columns

Abstract Changes in band profile, resolution, production, and yield with increasing sample size were determined for 1″ i.d. × 12″ preparative columns packed with 10 or 40 urn silica particles of the same origin. The results for a pure compound and for a mixture are compared. When a pure compound is injected, the efficiency of both columns decreases with increasing sample size. Although the 10-μm particle column is notably more efficient than the 40-μm particle column, for very large samples the plate numbers of both columns eventually become similar. When a binary mixture of isomers is injected, however, the 10-μm particle column provides a much larger yield and production of pure isomers than expected. When the sample size of this mixture is increased, the first eluted peak broadens to a lesser extent than if it were the peak of a pure component. It is better resolved from the more retained isomer than could be predicted on the basis of relative