New fractionation scheme for lipid classes based on "in-cell fractionation" using sequential pressurized liquid...

Area of Science:

• Analytical Chemistry
• Biochemistry
• Environmental Science

Background:

• Lipid fractionation is crucial for analyzing biological samples in various fields.
• Current methods for lipid separation can be time-consuming and solvent-intensive.
• Accurate lipid profiling is essential for understanding microbial communities, bioremediation, and food quality.

Purpose of the Study:

• To develop a new, efficient preparation scheme for fractionating neutral lipids from polar phospholipids.
• To optimize a two-step pressurized liquid extraction (PLE) combined with in-cell fractionation.
• To validate the method's performance against traditional lipid extraction and fractionation techniques.

Main Methods:

• A two-step pressurized liquid extraction (PLE) was optimized using specific solvent mixtures and temperatures.
• In-cell fractionation was achieved using silica-based sorbents placed within the PLE cartridge.
• Transmethylation of lipids was performed using trimethylchlorosilane/methanol to form methyl esters.

Main Results:

• The optimized PLE scheme effectively separated neutral lipids (acylglycerols, sterol esters, free fatty acids) from phospholipids.
• Silica-based sorbents (thermally pre-treated silicic acid, cyanopropyl-modified silica) provided clear lipid class boundaries.
• The new protocol demonstrated superior fractionation efficiency, reduced time, and lower solvent consumption compared to traditional methods.
• Transmethylation yielded complete methyl ester formation without artifacts, even for polyunsaturated fatty acids.

Conclusions:

• The proposed in-cell fractionation method offers a significant advancement in lipid analysis.
• This streamlined approach enhances the accuracy and efficiency of lipid profiling in diverse biological matrices.
• The method is applicable to critical areas such as microbial ecology, bioremediation monitoring, and food quality control.