title: Characterization of the polarity of reversed-phase liquid chromatographic stationary phases in the presence of 1-propanol using solvatochromism and multivariate curve resolution.
abstract: This work characterizes solvation effects in reversed-phase liquid chromatography in the presence of 1-propanol. The solvatochromic method combined with a multivariate curve resolution-alternating least-squares analysis method has been used to characterize two modified silica surfaces--phenyl bonded and C18 bonded silica in mobile-phase mixtures of methanol--water and acetonitrile--water in the presence of 1-propanol. The presence of a small amount of 1-propanol has been shown to affect mainly the polarity properties of the stationary phases while the mobile-phase properties are largely unaffected. The chain collapse mechanism for the C18 stationary phase at higher concentrations of water seems to be inhibited in the presence of 1-propanol, and partitioning is the predominant solute retention mechanism. The phenyl-based phase shows considerably different behavior from that of the C18 phase, and propanol appears to disrupt the pi-stacking interactions between the solute and the phenyl rings anchored to the silica support.
authors.affiliation: Department of Chemistry, Virginia Commonwealth University, Richmond 23284-2006, USA.
authors.forename: S
authors.initials: S
authors.lastname: Nigam
authors.forename: M
authors.initials: M
authors.lastname: Stephens
authors.forename: A
authors.initials: A
authors.lastname: de Juan
authors.forename: S C
authors.initials: SC
authors.lastname: Rutan