Enantiomers separation by nano-liquid chromatography: Use of a novel sub-2μm vancomycin silica hydride stationary phase

• Published in: Journal of Chromatography A 2015-02, Vol.1381, p.149-159
• Main Authors: Rocchi, Silvia, Rocco, Anna, Pesek, Joseph J., Matyska, Maria T., Capitani, Donatella, Fanali, Salvatore
• Format: Article
• Language: English
• Subjects: Capillaries; Chromatography; Enantiomers; Herbicides; Meters; Nano-liquid chromatography; Nanostructure; Non-steroidal anti-inflammatory drugs; Separation; Silicon dioxide; Standard deviation; Sub-2 μm silica hydride particles; Vancomycin; Vancomycin stationary phase
• ISSN: 0021-9673
• DOI: 10.1016/j.chroma.2015.01.015

•A novel sub-2μm vancomycin modified silica hydride particles was synthesized.•The CSP material was packed into capillaries and used in nano-LC.•Experiments were carried out studying both acidic and basic compounds.•The novel CSP offered high enantioresolution for acidic compounds.•Short analysis times were recorded using a conventional pump. A novel sub-2μm chiral stationary phase (CSP) was prepared immobilizing vancomycin onto 1.8μm diol hydride-based silica particles. The CSP was packed into fused silica capillaries of 75μm i.d. with a length of 11cm and evaluated by means of nano-liquid chromatography (nano-LC) using model compounds of both pharmaceutical and environmental interest (some non-steroidal anti-inflammatory drugs, β-blockers and herbicides). The study of the effect of the linear velocity of the mobile phase on chromatographic efficiency showed good enantioresolutions up to a value of 5.11 at the optimal linear velocity with efficiencies in terms of number of plates per meter in the range 51,650–68,330. The results were compared with the ones obtained employing 5μm vancomycin modified diol-silica particles packed in capillaries of the same i.d. For the acidic analytes the sub-2μm CSP showed better performances, the baseline chiral separation of several studied compounds occurred in an analysis time of less than 3min. Column-to-column packing reproducibility (n=3) expressed as relative standard deviation was in the range 2.2–5.8% and 0.5–7.7% for retention times and peak areas, respectively.