Characterization of calixarene- and resorcinarene-bonded stationary phases: I. Hydrophobic interactions

• Published in: Journal of Chromatography A 2003-12, Vol.1021 (1), p.71-82
• Main Authors: Sokoließ, Torsten, Schönherr, Janet, Menyes, Ulf, Roth, Ulrich, Jira, Thomas
• Format: Article
• Language: English
• Subjects: Analytical chemistry; Calixarene; Calixarenes; Chemistry; Chromatographic methods and physical methods associated with chromatography; Chromatography, High Pressure Liquid - methods; Exact sciences and technology; Hydrophobic interactions; Other chromatographic methods; Phenylalanine - analogs & derivatives; Phenylalanine - chemistry; Polycyclic Compounds - chemistry; Resorcinarene; Stationary phases; Steroids; Thioxanthenes
• ISSN: 0021-9673
• DOI: 10.1016/j.chroma.2003.09.014

New HPLC phases with supramolecular selectors on the basis of calixarenes and resorcinarenes were investigated for the first time by means of empirically based test mixtures. The tests, originally developed for common reversed phases, were chosen to evaluate fundamental chromatographic properties of the new materials. In the first part of these studies three descriptors (hydrophobic retention capacity— k hyd′, hydrophobic selectivity— α hyd, steric selectivity— α ster) were determined. Except of higher α ster values and α hyd values with some methods for the resorcinarene phase the phases with supramolecular selectors were classified as less hydrophobic possessing lower hydrophobic and steric selectivities compared to three RP-C 18 phases and a p- tert-butyl phenyl ether phase. The results were confirmed by means of a separation of geometric isomers of thioxanthenes. In contrast, in spite of lower k hyd′ and α hyd values calixarene phases were more selective than the Kromasil-C 18 phase in the separation of gestagenic and androgenic steroids due to specific interactions with the steroids of similar lipophilicity.