Thin-layer chromatography with eutectic mobile phases-preliminary results.

Area of Science:

• Analytical Chemistry
• Chromatography
• Phytochemistry

Background:

• Thin layer chromatography (TLC) is a widely used separation technique.
• Deep Eutectic Solvents (DES) are emerging as novel, environmentally friendly solvent systems.
• The application of DES in TLC, particularly natural DES (NADES), remains largely unexplored.

Purpose of the Study:

• To investigate the feasibility of using deep eutectic solvents (DES) as mobile phases for thin layer chromatography (TLC).
• To evaluate the chromatographic properties of various eutectic mixtures, including natural deep eutectic solvents (NADES).
• To develop an effective TLC method for separating alkaloids from the genus Chelidonium.

Main Methods:

• Screening of 25 eutectic mixtures, including NADES and novel phenolic/terpene-based DES, as mobile phases for TLC.
• Analysis conducted on classic and high-performance silica gel plates.
• Separation of five specific alkaloids (sanguinarine, coptisine, chelerythrine, chelidonine, berberine) using UV detection (366 nm).

Main Results:

• Demonstrated the successful application of DES in TLC, highlighting the critical role of eutectic interactions in separation.
• Achieved at least partial separation of alkaloids with most tested mobile phase modifications.
• Identified an equimolar menthol-phenol DES mixture with 35% methanol as the optimal mobile phase, enabling complete separation of all target alkaloids.

Conclusions:

• Deep Eutectic Solvents (DES) are viable and effective mobile phases for thin layer chromatography (TLC).
• The developed DES-based TLC system successfully separated complex alkaloid mixtures from both standard solutions and a real plant extract (Chelidonium maius).
• This research opens new avenues for green analytical chemistry applications using DES in chromatography.