A pH-stable, crosslinked stationary phase based on the thiol-yne reaction

Area of Science:

• Chromatography
• Materials Science
• Analytical Chemistry

Background:

• Stationary phases for chromatography require stability under extreme pH and temperature to broaden solute compatibility.
• Existing stationary phases often degrade under harsh conditions, limiting their application range.

Purpose of the Study:

• To develop a novel stationary phase with enhanced chemical and thermal stability for chromatographic separations.
• To characterize the selectivity and stability of the new phase under various mobile phase conditions.

Main Methods:

• A multi-step synthesis involving thiol-ene click chemistry on silica surfaces.
• Modification of silica with thiol-containing silanes, followed by polymerization of 1,4-diethynylbenzene (DEB) and 1,6-hexanedithiol.
• Characterization using Tanaka tests and hydrophobic subtraction modeling.

Main Results:

• The crosslinked thiol-yne (CTY) phase exhibited high shape selectivity and steric resistance.
• CTY phase demonstrated superior stability at pH 0.5 and pH 12.6 compared to sterically protected C18 phases.
• The phase showed minimal degradation over extended periods (114 hours) in highly aqueous mobile phases.

Conclusions:

• The developed CTY stationary phase offers exceptional robustness and stability in extreme chromatographic conditions.
• Its unique selectivity profile and durability make it a promising alternative to conventional reversed-phase materials.