Structure-function relationships in chromatographic stationary phases: Characterization of existing phases and improved strategies for materials fabrication

Abstract

Raman spectroscopy is used to determine rotational and conformational order of a series of high-density octadecylsilane stationary phases as a function of numerous chromatographic parameters. The effect of these conditions on the conformational order of the alkylsilanes offers information about molecular interactions at the chromatographic interface, which can be used to gain insight to the mechanisms of solute retention in reversed-phase liquid chromatography. The use of Raman spectroscopy to investigate fundamental interactions of chromatographic systems is also extended to studying ion exchange systems. In addition to the characterization of existing phases, alkylsilane-based stationary phases are fabricated using a novel solution modifier approach. This simple approach allows for the synthesis of materials that vary in surface coverage using the same reaction chemistry. Phases have alkylsilane structure, architecture, and give chromatographic performance comparable to existing phases of similar coverage.