title: Column selectivity in reversed-phase liquid chromatography. IV. Type-B alkyl-silica columns.
abstract: Columns for reversed-phase HPLC (RP-LC) can be characterized by five, retention-related parameters: H (hydrophobicity), S (steric selectivity), A (hydrogen-bond acidity), B (hydrogen-bond basicity), and C (cation-exchange behavior). In the present study, values of the latter parameters have been measured for 92 type-B (low metals content)alkyl-silica columns and compared to column properties such as ligand length,ligand concentration, pore diameter, and the presence or absence of end-capping. With the exception of five columns of unusual design, retention factors, k, for 16 representative test compounds were correlated with values of H, S, etc., within an average +/- 1.2% (1 standard deviation, SD), suggesting that all significant solute-column interactions are recognized by these five column parameters. A single-valued function F(s) is proposed to measure differences in selectivity for any two RP-LC columns whose values of H, S, etc., are known. This allows the easy selection of columns whose selectivity is desired to be either similar to or different from a starting column, for application in either routine analysis or method development.
authors.affiliation: LC Resources Inc., 3138 NE Rivergate, Bldg. 301C, McMinnville, OR 97128, USA.
authors.forename: Jonathan J
authors.initials: JJ
authors.lastname: Gilroy
authors.forename: John W
authors.initials: JW
authors.lastname: Dolan
authors.forename: Lloyd R
authors.initials: LR
authors.lastname: Snyder
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation*