Analytical characterization of PEG polymers by MEKC.

Area of Science:

• Analytical Chemistry
• Polymer Science
• Chromatography

Background:

• Polyethylene glycols (PEGs) are widely used polymers with varying molecular masses.
• Accurate characterization of PEG molecular mass and distribution is crucial for quality control and safety.
• Traditional methods for PEG analysis can be time-consuming and complex.

Purpose of the Study:

• To develop a rapid and accurate method for characterizing polyethylene glycols (PEGs) up to 2000 Da.
• To introduce UV-detectable chromophore groups onto PEGs for enhanced detection.
• To apply the developed method for PEG analysis in diverse real-world samples.

Main Methods:

• Microemulsion electrokinetic chromatography (MEKC) with UV detection was employed for PEG separation.
• A rapid microwave-assisted derivatization using phenyl isocyanate was developed for PEG functionalization (60s reaction time).
• Optimized chromatographic conditions were established based on PEG molecular weight for effective oligomer separation.

Main Results:

• The method successfully characterized PEGs with average molecular masses up to 2000 Da.
• Calculated weight-average molecular mass, number-average molecular mass, and polydispersity closely matched certified standards.
• High precision was achieved in the characterization of different PEG oligomers.

Conclusions:

• The developed MEKC method, coupled with rapid microwave-assisted derivatization, provides an efficient means for PEG characterization.
• Ethylene glycol served as an effective internal standard for low-molecular-weight PEG analysis.
• The method demonstrated robust applicability in analyzing PEGs in various consumer products, including eye drops, toothpaste, tap water, and makeup remover.