CHROMATOGRAPHY, Vol. 26 (2005), No. 2, pp. 63-66

Octadecylsilane.bonded silica (ODS) columns are the most widely used columns for research and quality control in the pharmaceutical and chemical industries. We examined the retention behavior of various compounds on 2 kinds of newly developed ODS columns. Both packings were exhaustively reacted with end.capping reagent. Both columns showed excellent asymmetry factor with Desipramine, basic compound It was confirmed that the retention of neutral compounds on ODS columns increased with ODS ligand density. On the other hand, TSKgel ODS-100 V, a column with low C 18 ligand density followed by exhaustive end.capping, strongly retained polar compounds compared with TSKgel ODS-100 Z, a column with high C 18 ligand density followed by exhaustive end-capping. Longer retention for polar compounds was assumed to be the ability of such analytes to interact with water-rich layers near the silica surface.