Techniques for High-Performance Liquid-Liquid and Ion Exchange Chromatography with Controlled Surface Porosity Column Packings

Abstract

The speed of liquid-liquid and ion exchange chromatographic separations can be significantly increased with columns of controlled surface porosity (CSP) packings. Electron micrographs show that these CSP materials provide a relatively large surface area on which a thin film of sorbent may be uniformly dispersed; the open-structured surface is readily accessible to the mobile phase. The high speed capabilities of these packings are primarily due to the low level of peak broadening resulting from mass transfer effects. Important parameters for providing highly efficient liquid chromatographic separations include: the type of column tubing used, column configuration, and the volume of liquid sample injected into the column. Liquid chromatographic analyses are carried out with CSP packings in a manner analogous to gas chromatography with regard to time and column efficiency. Liquid-liquid chromatographic columns containing CSP support have been routinely used for the precise assay of materials which cannot be analyzed by other means. Separations of test systems show that the CSP cation and anion columns provide separations at least an order of magnitude faster than conventional gel ion exchange chromatography.