Monitoring the Interactions of Tocopherol Homologues with Reversed-Phase Stationary HPLC Phases by 1H Suspended-State Saturation Transfer Difference High-Resolution/Magic Angle Spinning NMR Spectroscopy

• Published in: Analytical chemistry (Washington) Vol. 79; no. 21; pp. 8323 - 8326
• Main Authors: Schauff, Siri, Friebolin, Volker, Grynbaum, Marc David, Meyer, Christoph, Albert, Klaus
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.11.2007
• Subjects: Acrylic Resins - analysis; Analytical chemistry; Chemistry; Chromatographic methods and physical methods associated with chromatography; Chromatography, High Pressure Liquid - methods; Exact sciences and technology; Hydrophobic and Hydrophilic Interactions; Magnetic Resonance Spectroscopy - methods; Molecular Structure; Other chromatographic methods; Particle Size; Polyethylenes - analysis; Reproducibility of Results; Sensitivity and Specificity; Spectrometric and optical methods; Stereoisomerism; Tocopherols - analysis; High resolution; HPLC chromatography; Hydrophobic interaction; NMR spectrometry; Selectivity; Protein; Isomer; Magic angle; Reversed phase chromatography; Separation process; Tocopherols; Monitoring; Stationary phase
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac071069t

The separation process in reversed-phase high-performance liquid chromatography employing C18 phases is mainly due to hydrophobic interactions. The separation of tocopherol isomers, exhibited by the C30 phases, however, is additionally driven by shape selectivity. This phenomenon is investigated by suspended-state nuclear magnetic resonance spectroscopy using the saturation transfer difference technique, which was originally introduced to study protein−ligand interactions. The interaction strength between β-/γ-tocopherol and three different stationary phases was estimated qualitatively. The nuclear magnetic resonance data are compared to chromatographic data, and a similar mode of interaction between the analytes and the stationary phases is elucidated.