HILIC characterization: Estimation of phase volumes and composition for a zwitterionic column
| Autor: | Martí Rosés, Lídia Redón, Xavier Subirats |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Hydrophilic interaction chromatography
010401 analytical chemistry Liquid chromatography Analytical chemistry 02 engineering and technology 021001 nanoscience & nanotechnology Cromatografia de líquids 01 natural sciences Biochemistry 0104 chemical sciences Analytical Chemistry chemistry.chemical_compound Homologous series Column chromatography Adsorption Fluid dynamics chemistry Volume (thermodynamics) Dinàmica de fluids Phase (matter) Environmental Chemistry Methanol 0210 nano-technology Acetonitrile Spectroscopy |
| Zdroj: | Dipòsit Digital de la UB Universidad de Barcelona |
| ISSN: | 0003-2670 |
| DOI: | 10.1016/j.aca.2020.06.035 |
| Popis: | A methodology for the estimation of the different phase volumes in HILIC is presented. For a ZIC-HILIC column the mobile phase volume (hold-up volume) is determined in several acetonitrile- and methanol-water compositions by a Linear Free Energy Relationships (LFER) homologous series approach involving n-alkyl-benzenes, -phenones, and -ketones. We demonstrate that the column works as a HILIC column when the mobile phase contains high and medium proportions of methanol or acetonitrile. However, for acetonitrile contents below 20%, or 40% for methanol, same column works in RPLC. In between, a mixed HILIC-RPLC behavior is observed, and solutes of low molecular volume are retained as in HILIC mode, but the largest ones show RPLC retention. From the homologous series retention data and pycnometric measurements involving the pure organic solvents and their mixtures with water, the mean solvent composition of the water-rich transition layers between column functionalization and the bulk mobile phase, which act as stationary phase, is estimated. Finally, the phase ratio between stationary and mobile phases is also estimated for each eluent composition, allowing the calculation of the corresponding stationary phase volumes. All volumes are strongly dependent on the water content in the eluent, especially when acetonitrile is selected as mobile phase constituent. In HILIC mode, when the water content in the hydroorganic mobile phase increases, the volumes of mobile phase decrease, but the volumes of stationary phase (mainly the water layer adsorbed onto the bonded-phase and the water-enriched interface) increase. However, at high water concentrations, where the column works in RPLC mode, the mobile phase volume increases and the stationary phase (which is now the bonded zwitterion) volume decreases when increasing the water percentage in the mobile phase. |
| Databáze: | OpenAIRE |
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