Development of High Surface Area of Carbon Packing Materials for High Performance Liquid Chromatography

The retention of polar compounds, the separation of structural isomers and thermal stability of carbonaceous materials make them very attractive for use as stationary phases in high performance liquid chromatography (HPLC). Unfortunately, most of the carbonaceous stationary phases prepared to date exhibit a number of characteristics which are chromatographically undesirable. Among the most detrimental are energetically heterogeneous surfaces, inadequate mechanical strength and undesirable pore structures. Porous graphitic carbon (Hypercarb) and carbon clad zirconia are the two most successful carbon packings for HPLC. Although Hypercarb has insufficient mechanical stability, it has been widely used for many applications. The unequalled chemical and thermal stability of C/ZrO2 have also proven quite useful as a packing material in HPLC. However, the characteristically low surface area of commercial porous zirconia limits the broader application of C/ZrO2, especially for two-dimensional liquid chromatography (LC x LC) where high retentivity and therefore high stationary phase surface area are highly desirable. We aimed to prepare carbonaceous packing material with higher surface areas compared to C/ZrO2, without sacrificing the unique chromatographic properties of carbonaceous materials.;In this thesis, we developed new robust carbon phases on high surface area of 5 mum porous alumina and silica to address the limitations of current carbon phases. These new carbons showed chromatographic usefulness as packing materials and provided higher retentivity than C/ZrO2 while maintaining all the desired properties of other carbons including the unique selectivity. As silica is preferred support due to its wide variety of size and types and its availability, we proposed a new method to develop carbon phases on silica. In addition to the 5 mum fully porous carbon packing, we also successfully prepared carbon clad core shell silica (2.7 mum) by applying the new method. Consequently, the resulting material improved the resolving power of LC x LC as used for the second dimension column. Considering the wide variety of sizes and types of silica available, our new method shows great potential to developing various types of carbonaceous materials for HPLC.