Analysis of Ethylene Carbonate and Ethyl Methyl Carbonate by GC/FID on a Thermo Scientific TraceGOLD TG-35MS Column

Significance of the Topic

Ethylene carbonate (EC) and ethyl methyl carbonate (EMC) serve as essential electrolyte components in lithium-ion batteries, influencing performance, safety and longevity. Accurate quantification of these organic carbonates is also critical in polymer synthesis and plasticizer production. Reliable chromatographic methods ensure consistent manufacturing quality and robust process control in energy storage and related industries.

Objectives and Study Overview

This study demonstrates a gas chromatography–flame ionization detection (GC/FID) method on a Thermo Scientific TraceGOLD TG-35MS column for simultaneous quantification of EC and EMC. The primary goal was to achieve sharp, reproducible peaks and consistent peak area ratios across multiple injections, supporting quality assurance requirements in battery electrolyte analysis.

Methodology and Instrumentation

Sample Preparation:

• Mixture of EMC/EC at 70:30 ratio diluted to 2.2 mg mL^–1 in dichloromethane.

GC/FID Configuration:

• Instrument: Thermo Scientific Focus GC with TriPlus autosampler.
• Column: TraceGOLD TG-35MS (30 m × 0.25 mm i.d. × 0.25 µm film, 35% diphenyl/65% dimethyl polysiloxane).
• Carrier gas: Helium at 1.0 mL min^–1 (constant flow).
• Oven program: 100 °C (2.5 min hold) to 200 °C (4 min hold) at 30 °C min^–1.
• Injector: Split mode, ratio 70:1, temperature 200 °C.
• Detector: FID at 250 °C; air 350 mL min^–1, hydrogen 35 mL min^–1, nitrogen makeup 30 mL min^–1.

Auxiliary Components:

• 2 mL clear vials with Si/PTFE seals.
• Split/splitless liners with Siltek deactivation.
• Graphite ferrules and standard GC syringes.

Main Results and Discussion

The method delivered sharp, symmetric peaks for EMC (retention ~2.38 min) and EC (retention ~4.93 min). Five consecutive injections yielded consistent EC/EMC peak area ratios around 0.31, demonstrating excellent repeatability. Key observations include:

• Peak symmetry supporting accurate integration.
• Stable retention times enabling reliable identification.
• Reproducible peak area ratios across runs.

Benefits and Practical Applications

This GC/FID approach offers battery manufacturers and analytical laboratories an efficient, cost-effective means to monitor electrolyte purity and composition. The robust performance facilitates routine quality control, research on alternative solvents and troubleshooting of battery formulations.

Future Trends and Opportunities

The analytical technique can evolve through:

1. Integration with mass spectrometric detection for enhanced selectivity.
2. Expansion to other carbonate and organic solvent systems.
3. High-throughput or fast-chromatography adaptations.
4. Online process monitoring in battery cell production.
5. Green solvent applications and miniaturized GC platforms.

Conclusion

The described GC/FID method on a TraceGOLD TG-35MS column provides reliable, reproducible quantification of EC and EMC. Its robustness, ease of use and consistent performance make it an ideal choice for quality control in battery electrolyte manufacturing and related chemical processes.

Reference

• Wiedemer B. Thermo Fisher Scientific Application Note ANCCSETHCARTG (2012).