A simple subcritical chromatographic test for an extended ODS high performance liquid chromatography column classification

• Published in: Journal of Chromatography A Vol. 1100; no. 1; pp. 45 - 59
• Main Authors: Lesellier, Eric, Tchapla, Alain
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 23.12.2005; Elsevier
• Subjects: Analytical chemistry; Chemistry; Chromatographic methods and physical methods associated with chromatography; Chromatography, High Pressure Liquid - instrumentation; Column classification; Exact sciences and technology; Hydrophobicity; ODS stationary phases; Other chromatographic methods; Reproducibility of Results; Sensitivity and Specificity; Silanophilic interactions; Silicon Dioxide - chemistry; Steric separation factor; Steric separation factor; Silanophilic interactions; Column classification; Hydrophobicity; ODS stationary phases; HPLC chromatography; Supercritical fluid chromatography; Subcritical fluid chromatography; Reversed phase chromatography; Classification; Lipophilicity; Bonded stationary phase; Physicochemical properties
• ISSN: 0021-9673
• DOI: 10.1016/j.chroma.2005.09.016

This paper describes a new test designed in subcritical fluid chromatography (SFC) to compare the commercial C18 stationary phase properties. This test provides, from a single analysis of carotenoid pigments, the absolute hydrophobicity, the silanol activity and the steric separation factor of the ODS stationary phases. Both the choice of the analytical conditions and the validation of the information obtained from the chromatographic measurements are detailed. Correlations of the carotenoid test results with results obtained from other tests (Tanaka, Engelhard, Sander and Wise) performed both in SFC and HPLC are discussed. Two separation factors, calculated from the retention of carotenoid pigments used as probe, allowed to draw a first classification diagram. Columns, which present identical chromatographic behaviors are located in the same area on this diagram. This location can be related to the stationary phase properties: endcapping treatments, bonding density, linkage functionality, specific area or silica pore diameter. From the first classification, eight groups of columns are distinguished. One group of polymer coated silica, three groups of polymeric octadecyl phases, depending on the pore size and the endcapping treatment, and four groups of monomeric stationary phases. An additional classification of the four monomeric groups allows the comparison of these stationary phases inside each group by using the total hydrophobicity. One hundred and twenty-nine columns were analysed by this simple and rapid test, which allows a comparison of columns with the aim of helping along their choice in HPLC.