Univerzita Pardubice Fakulta chemicko- technologická

Univerzita Pardubice

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Studenti
English

Publikace detail

Multi-dimensional liquid chromatography: off-line and on-line approaches

Autoři: Jandera Pavel | Hájek Tomáš | Staňková Magda

Rok: 2016

Druh publikace: ostatní - přednáška nebo poster

Strana od-do: nestránkováno

Tituly:

Jazyk	Název	Abstrakt	Klíčová slova
eng	Multi-dimensional liquid chromatography: off-line and on-line approaches	We developed an automated dual LCxLC approach, enabling large essential changes in separation selectivity on a single column by large modulation of retention mechanism adjusting the mobile phase by adjusting the composition of aqueous-organic mobile phases, from high concentrations (60-95%) of acetonitrile for polar compounds, to reversed-phase mechanism showing completely different selectivity and elution order at less than 40% organic solvent in water, in alternating gradient elution runs during a single experiment on a single column. A monolithic zwitterionic sulfobetaine polymethacrylate micro-column BIGDMA-MEDSA, designed in our laboratory, shows such a dual retention mechanism: HILICIn acetonitrile-rich mobile phase, and RP with major role of hydrophobic interactions in highly aqueous mobile phases. The BIGDMA-MEDSA column can be used in the first dimension of two-dimensional reversed-phase (RP) and HILIC modes, coupled with an alkylbonded core-shell or silica-based monolithic column in the second dimension, for alternating HILIC×RP and RP×RP comprehensive two-dimensional separations of a single sample. During the HILIC×RP period, a gradient of decreasing acetonitrile gradient is used for separation in the first dimension, so that at the end of the gradient the polymeric monolithic micro-column is equilibrated with a highly aqueous mobile phase and is ready for repeated sample injection, this time for separation under reversed-phase gradient conditions with increasing concentration of acetonitrile in the first dimension. The fast repeating reversed-phase gradients on a short silica-monolithic or a core-shell column in the second dimension can be optimized independently of the actual running first-dimension gradient program. As the alternating HILIC and RP separations on the first-dimension zwitterionic methacrylate column are based on different retention mechanisms.	HILIC; RP; two-dimensional liquid chromatography; monolithic columns; LCxLC