Menthol-Based (Deep) Eutectic Solvents: A Review on Properties and Application in Extraction

Area of Science:

• Green Chemistry
• Analytical Chemistry
• Materials Science

Background:

• Deep eutectic solvents (DESs) are gaining interest as environmentally friendly alternatives to traditional solvents.
• Hydrophobic DESs are increasingly utilized in extraction technologies, particularly for sample preparation.
• The properties of DESs are tunable based on their hydrogen bond donor and acceptor components.

Purpose of the Study:

• To review available literature on the physicochemical properties of menthol-based eutectic solvents.
• To summarize the application of menthol-based DESs as extraction media.
• To discuss the definition and appropriate use of the term "DES" for low-melting point mixtures.

Main Methods:

• Literature review of physicochemical properties of menthol-based DESs.
• Analysis of published data on the application of these DESs in extraction processes.
• Discussion on the classification of eutectic mixtures.

Main Results:

• Menthol-based DESs exhibit diverse physicochemical properties suitable for various extraction tasks.
• These solvents have demonstrated effectiveness in extracting metal ions, organic compounds, and biomolecules.
• The review highlights the need for consistent terminology regarding DES classification.

Conclusions:

• Menthol-based DESs represent a promising class of green solvents for extraction and sample preparation.
• Further research is needed to fully understand and optimize their extraction capabilities.
• Standardization of terminology for eutectic mixtures is recommended for clarity in the field.