Characterization of Carbon-Modified Silicas for Use in Analytical Liquid Chromatography

We have recently developed a series of novel carbon-modified porous silica materials for use in analytical and preparative separations, and as solid-phase extraction media. The analytical materials exhibit unique characteristics compared to other commercially available carbon phases as they are substantially more stable at high pressures and exhibit acceptable mass transfer characteristics. Users of carbon-based phases are aware that some compounds are very difficult to elute from existing commercial carbon-based materials. The new materials described here significantly address this problem through both the ability to adjust the carbon loading on the underlying substrate, and the use of a relatively inert substrate. We will report on the basic characterization of a suite of materials that cover a wide range of carbon loading, including: retention of non-polar and polar compounds, and selectivity. We will also show the potential of these materials for use in two-dimensional separations.