Title: Application of Monolithic Stationary Phases in Solid-Phase Extraction and Pharmaceutical Analysis
Volume: 6
Issue: 3
Author(s): Gengliang Yang and Haiyan Liu
Affiliation:
Keywords:
Monolithic Column, Solid-phase Extraction, Pharmaceutical Analysis, Separation, HPLC, CEC
Abstract: Development of new style chromatographic packing materials and improvement of their performance are important in the study of pharmaceutical analysis. Monoliths are separation media in a format that can be compared with a single large particle that does not contain the interparticular voids typical of packed beds. In recent years, monolithic supports as stationary phases in high-performance liquid chromatography (HPLC) and capillary electrophoresis (CE) have gained significant interest due to their ease of preparation, high reproducibility, versatile surface chemistries and fast mass transport. Generally, depending on the nature of the monolithic material, organic polymer-based monolithic columns and silica-based monolithic columns can be identified. The silica monoliths prepared from tetraalkoxysilane by a sol – gel method can provide either micrometer-size through-pores or high specific surface areas and can be well suited for small molecules in HPLC modes. Organic polymer-based monoliths including monolithic molecularly imprinted polymers have been applied not only in separation and analysis of biomacromolecules, but also in treatments of the samples before injected into the chromatograph in biological fluids because it allows the simultaneous removal of matrix compounds and preconcentration of the analytes. The most commonly reported organic polymers are based on polystyrenes, polymethacrylates and polyacrylamides. Capillary electrophoresis with both organic polymer-based and silica-based monolithic columns has also been used for the separation of small molecules. This review summarizes the current achievements and their application of organic polymer-based monolithic columns and silica-based monolithic columns for both HPLC and CE in solid-phase extraction (SPE) and pharmaceutical analysis. The potential of these columns is demonstrated with separations involving various drugs in different chromatographic modes.
