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Column-in-valve designs to minimize extra-column volumes
Vincent Pepermans1, Michael T Rerick2, Bart Degreef1
1Department of Chemical Engineering, Vrije Universiteit Brussel, Brussels, Belgium.
Journal of Chromatography. A
|January 1, 2021
Summary
Researchers developed in-house column cartridges for ultra-fast liquid chromatography (LC) separations, aiming to reduce band broadening. However, the fabricated columns exhibited low separation efficiency, potentially due to packing issues with sub-2-μm particles.
Area of Science:
- Analytical Chemistry
- Chromatography
Background:
- Ultra-fast separations in 2D and 3D-LC require minimizing extra-column band broadening and pressure-drop.
- Rotor-stator valves are common in LC systems, but direct column integration can be challenging.
Purpose of the Study:
- To design and evaluate in-house built column cartridges for direct integration with rotor-stator valves.
- To assess the performance of these cartridges in terms of extra-column band broadening and separation efficiency.
- To compare the in-house cartridges with a commercial screw-in column cartridge.
Main Methods:
- Fabrication of two designs of in-house column cartridges.
- Integration of cartridges directly into a commercial rotor-stator valve.
- Evaluation of extra-column band broadening using UV detection.
- Assessment of separation efficiency and reduced minimal plate height (h) with sub-2-μm particles.
Main Results:
- The system achieved very low extra-column band broadening (0.05–0.1 μL²).
- In-house fabricated columns showed low separation efficiency (h ≈ 7, N ≈ 2200).
- A commercial cartridge with similar dimensions exhibited comparable poor performance.
Conclusions:
- Directly screwing in-house column cartridges into rotor-stator valves effectively minimizes extra-column band broadening.
- The low separation efficiency observed in both in-house and commercial cartridges may stem from packing difficulties associated with sub-2-μm particles in narrow-diameter columns (0.75–1 mm i.d.).
- Further research into packing methodologies for narrow-bore columns is warranted.
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