Ionic liquids as surfactants in micellar liquid chromatography

Area of Science:

• Analytical Chemistry
• Separation Science

Background:

• Ionic liquids (ILs) are explored as novel surfactants in Liquid Chromatography (LC).
• Traditional surfactants like Sodium Dodecyl Sulfate (SDS) have limitations.
• 1,4-thiosemicarbazide derivatives are a class of organic compounds requiring efficient separation methods.

Purpose of the Study:

• To investigate the application of ILs as surfactants in the micellar liquid chromatography (MLC) of 1,4-thiosemicarbazide derivatives.
• To establish optimal HPLC conditions for IL-based MLC.
• To compare the performance of IL surfactants with SDS.

Main Methods:

• High-Performance Liquid Chromatography (HPLC) with UV detection.
• Conductivity measurements for critical micelle concentration (CMC) determination.
• Evaluation of two stationary phases: RP-C18 and cyanopropyl.
• Comparison of IL surfactant with SDS under micellar conditions.

Main Results:

• Optimal HPLC conditions including UV transparency, low CMC, salt additives, and solvent composition were identified for IL surfactants.
• The CMC of the chosen IL surfactant was determined.
• Both RP-C18 and cyanopropyl phases showed suitability under micellar conditions.
• IL surfactant performance was comparable to SDS.
• MLC conditions were validated for predicting distribution coefficients in IL-based aqueous two-phase systems.

Conclusions:

• Ionic liquids are viable and effective surfactants for MLC of 1,4-thiosemicarbazide derivatives.
• The developed MLC method serves as a predictive tool for partitioning in IL-based aqueous two-phase systems.
• This research offers a novel approach for chromatographic separations and predicting phase behavior.