Characterization of stationary phases for reversed-phase chromatography.

Retention characteristics of seven silica-based chromatographic columns (Bidentate C18, Silica-hydride, Spherisorb ODS-1, Resolve C18, XTerra C18, XBridge Phenyl and Blaze C8 Polydentate) were compared. The columns differ in the character of the support, including silica type B, hydrosilated silica, and hybrid silica gel with incorporated methyl groups, or ethylene bridges; further in the type of chemically bonded stationary phase, including C(18), C(8) and phenyl ligands, endcapped and non-endcapped with single point, bidentate and polydentate multi-point attachment to the adsorbent surface. Special attention was focused on hydrophobic and polar selectivity, silanol activity and anion-exclusion. The columns were compared and classified on the basis of the results of the classical column performance tests, retention of homologous n-alkylbenzenes over a broad composition range of aqueous-organic mobile phases and of naphthalene sulphonic acids in aqueous mobile phases without organic solvents.