Effects of mobile phase composition on retention and selectivity in achiral supercritical fluid chromatography

• Published in: Journal of Chromatography A Vol. 1302; pp. 152 - 162
• Main Authors: West, Caroline, Lesellier, Eric
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 09.08.2013; Elsevier
• Subjects: Acetonitrile; Acetonitriles - chemistry; Analysis; Analytical chemistry; Anti-Inflammatory Agents, Non-Steroidal; barbiturates; Biological and medical sciences; carbon dioxide; Chemistry; Chromatographic methods and physical methods associated with chromatography; Chromatography; Chromatography, Supercritical Fluid - methods; cluster analysis; Columns (structural); Ethanol; Ethanol - chemistry; Ethyl alcohol; Exact sciences and technology; flavanones; Flavanones - analysis; General pharmacology; isopropyl alcohol; Medical sciences; methanol; Method development; Methyl alcohol; Mobile phase composition; nonsteroidal anti-inflammatory agents; Other chromatographic methods; Pharmacology. Drug treatments; quantitative analysis; Selectivity; silica; Solvation parameter model; solvents; Stationary phases; Supercritical fluid chromatography; Supercritical fluids; Selectivity; Stationary phases; Method development; Solvation parameter model; Mobile phase composition; Supercritical fluid chromatography; Cluster analysis; Phase composition; Property composition relationship; Acetanilide; Hierarchical classification; Chromatographic retention; Prediction; Mobile phase; Flavonoid; Flavanone derivatives; Non steroidal antiinflammatory agent; Solvation; Homologous series; Pyrimidine derivatives; Property structure relationship; Barbiturates; Chemometrics; Stationary phase
• ISSN: 0021-9673; 1873-3778
• DOI: 10.1016/j.chroma.2013.06.003

•Four co-solvents were tested with seven achiral columns.•Acetonitrile is most different from the alcohol modifiers.•Ethanol is an interesting ecofriendly option.•Column should be selected first when developing an achiral SFC method.•Co-solvent nature essentially affects retention and peak shape in achiral SFC. In supercritical fluid chromatography (SFC), the effects of adding a co-solvent to carbon dioxide are numerous. In this work, the changes in retention and selectivity occurring when the nature of the co-solvent (methanol, ethanol, isopropanol, acetonitrile) in the SFC mobile phase is varied, are studied on seven columns with different stationary phase chemistry (cyanopropyl-, pyridine-ethyl-, phenyl-oxypropyl-, phenyl-propyl-, phenyl-hexyl-, pentafluorophenyl-propyl- and octadecyl-bonded silica). Hierarchical cluster analysis and quantitative structure–retention relationships with the solvation parameter model are employed to evaluate these effects, based on the observed retention for over a hundred probe compounds. It appears that some columns are somewhat more affected than others by the change of solvent nature. Acetonitrile induces the strongest differences, essentially due to its poor capabilities as an eluent for bases and possibly because it does not adequately cover residual silanol groups. Ethanol appears to be a possible green alternative to the most-used methanol. Some hints on a possible partition–adsorption mixed mechanism are offered. Finally, sample applications with three different test mixtures relevant to cosmetic and pharmaceutical applications (flavanones, non-steroidal anti-inflammatory drugs and barbiturates) are presented.