title: Dependence of reversed-phase retention of ionizable analytes on pH, concentration of organic solvent and silanol activity.
abstract: In reversed-phase chromatography, the retention of ionizable analytes is influenced by the ionic properties of the packing caused by surface silanol groups. We have measured the ion-exchange properties of both reversed-phase bonded phases and their underlying base materials. The probe used in this part of the study was bretylium tosylate. The acquired knowledge is then used for a complete and quantitative understanding of the retention behavior of ionizable compounds as a function of the pH of the mobile phase and the solvent composition. We have studied the retention pattern of a broad range of acids, bases, and polyfunctional analytes over the pH range from 2 to 11 and from water to 80% acetonitrile. A few application examples demonstrate the relevant findings.
authors.affiliation: Waters Corporation, Milford, MA 01757, USA. uwe_neue@waters.com
authors.forename: U D
authors.initials: UD
authors.lastname: Neue
authors.forename: C H
authors.initials: CH
authors.lastname: Phoebe
authors.forename: K
authors.initials: K
authors.lastname: Tran
authors.forename: Y F
authors.initials: YF
authors.lastname: Cheng
authors.forename: Z
authors.initials: Z
authors.lastname: Lu
mesh_terms: D006863:Hydrogen-Ion Concentration; D009930:Organic Chemicals / Q000737:chemistry*; D012821:Silanes / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry*
chemical_list: D009930:Organic Chemicals; D012821:Silanes; D012997:Solvents; C082343:silanol