Study of conical columns with 10° opening angle for preparative liquid chromatography

The efficiency and sample capacity of conical liquid chromatographic columns with 10° opening angle were studied at different ratio of cross section areas of inlet to outlet (Ain/Aout) and column dimension. As the Ain/Aout ratio changed from 4 to 2.25, the reduced plate height (h) was reduced and the h value decreased 12% when the column dimension was scaled up proportionally because of relatively smaller dead volume on both end of the column. Compared to cylindrical columns having corresponding lengths and volumes, the conical columns with 10° opening angle were superior in column efficiency, resolution and the maximum peak concentration at column outlet; the loadability of conical column was improved 30-40% on injection volume and 50-60% on sample mass, respectively, over cylindrical columns.