Arc HPLC Aqueous SEC/GPC Separation of PEO/PEG

Significance of the Topic

The accurate determination of polymer molecular weight distribution is essential across industries ranging from pharmaceuticals to materials science. Size exclusion chromatography (SEC), also called gel permeation chromatography (GPC), provides a reliable approach to characterize polymers such as polyethylene glycol (PEG) and polyethylene oxide (PEO). Consistent flow control and advanced data processing are critical to achieving reproducible, high-resolution separations that inform both research and quality control.

Objectives and Study Overview

This application brief evaluates the performance of a modern HPLC platform—Waters Arc HPLC System—coupled with Empower 3 software for aqueous SEC/GPC of PEO/PEG standards. The study aims to demonstrate:

• Precision of isocratic flow delivery under real-world conditions
• Capability of achieving narrow peak reproducibility
• Effectiveness of two Ultrahydrogel Linear columns for extended molecular weight range up to 7 MDa
• Utility of Empower 3’s built-in GPC calculations and reporting features

Methodology and Instrumentation

An isocratic separation was carried out using the Arc HPLC System equipped with dual Ultrahydrogel Linear columns. The mobile phase and flow rate parameters were defined to optimize polymer resolution over a 30-minute run. Narrow PEO/PEG standards spanning a wide molecular weight range were injected in six replicates to assess retention time precision. Empower 3 software’s GPC option generated calibration curves, molecular weight averages (Mn, Mw, Mp), and polydispersity indices.

Used Instrumentation

• Waters Arc HPLC System with precision isocratic pump
• Empower 3 Chromatography Data Software, GPC option
• Two Ultrahydrogel Linear columns (nominal range up to 7 million Da)

Main Results and Discussion

The system demonstrated exceptional flow precision, yielding relative standard deviations below 0.3% for both retention time and Mp in six successive injections of mixed PEO/PEG standards. The overlay of chromatograms confirmed consistent peak shapes and retention profiles. Empower 3 provided automated calculation of molecular weight distribution and cumulative percent, along with key parameters such as Mn, Mw, Mp, Mz, Mz+1, and polydispersity. Column efficiency monitoring via plate count further highlighted the stability of the Ultrahydrogel columns over the analysis sequence.

Benefits and Practical Applications

Key advantages observed include:

• Reliable isocratic flow ensuring reproducible separations
• Rapid 30-minute analysis for high throughput
• Comprehensive reporting directly within Empower 3, reducing manual spreadsheet work
• Broad molecular weight coverage suitable for complex polymer blends

These features support quality control labs, polymer research and development, and regulatory compliance requirements.

Future Trends and Applications

Advances in column chemistries and software algorithms will push the boundaries of SEC/GPC toward lower detection limits and faster analyses. Integration with multi-detector setups (e.g., light scattering, viscometry) and automated data workflows will further enhance polymer characterization. Emerging applications include biopolymer sizing, nanomaterials analysis, and real-time process monitoring.

Conclusion

The Waters Arc HPLC System combined with Empower 3 software delivers high-precision flow control and robust data processing for aqueous SEC/GPC of PEO/PEG standards. The setup achieves rapid, reproducible results across a wide molecular weight range, making it a valuable tool for both fundamental studies and routine quality assessments.

References

1. Waters Arc HPLC System Product Information, Waters Corporation.
2. GPC/SEC FAQs, Waters Corporation.
3. Timilsena et al., Carbohydrate Polymers, 2016.
4. Waters Ultrahydrogel Columns Care and Use Manual.
5. Waters Empower GPC Software Guide.