Analysis of flavors in E-liquid

Importance of Flavor Analysis in E-liquids

Flavor compounds such as diacetyl (2,3-butanedione), pentanedione (2,3-pentanedione), and acetoin contribute to the sensory profile of e-liquids but are associated with potential health risks when present at high levels. Accurate quantification is essential for ensuring consumer safety, regulatory compliance, and consistent product quality.

Objectives and Study Overview

This application note describes a GC-MS based protocol designed to separate and quantify key flavor diketones in flavored e-liquids. The method aligns with technical specifications from the China Electronics Chamber of Commerce, focusing on sensitivity, selectivity, and reproducibility for routine quality control.

Methodology and Instrumentation

• Gas Chromatograph Mass Spectrometer: Shimadzu GCMS-QP2020 NX
• Column: SH-I-624Sil MS, 60 m × 0.32 mm I.D., film thickness 1.80 μm
• Temperature Program: 60 °C (2 min) → 10 °C/min to 120 °C (2 min) → 25 °C/min to 240 °C (12 min)
• Injection: 240 °C, split mode (20:1)
• Carrier Gas: Helium, constant linear velocity at 25.8 cm/s
• Ionization: Electron Impact (EI), interface at 250 °C, ion source at 200 °C
• Detection: Selected Ion Monitoring (SIM) targeting diagnostic ions for each analyte

Main Results and Discussion

The method achieved baseline separation of diacetyl, pentanedione, and acetoin with distinct retention times and minimal matrix interference. SIM acquisition enabled low detection limits and a linear response across relevant concentration ranges. Reproducibility studies indicated relative standard deviations below 5%, confirming the method’s robustness.

Benefits and Practical Applications

• High selectivity and sensitivity through SIM detection
• Rapid analysis cycle suitable for high throughput
• Robust performance for routine QA/QC in manufacturing
• Compliance with safety standards and technical specifications

Future Trends and Potential Uses

• Expansion of analyte panels to include emerging flavoring agents and thermal degradation products
• Integration with automated sample preparation for improved workflow
• Adoption of high-resolution or tandem mass spectrometry for non-targeted screening
• Development of portable GC-MS platforms for on-site quality assessment

Conclusion

The described GC-MS SIM method using the SH-I-624Sil MS column provides a reliable, sensitive, and efficient approach for quantifying flavor diketones in e-liquids. Its performance supports regulatory compliance and quality assurance in the vaping industry.

Reference

• Application News 03-GCMS-415 (JP, ENG), Shimadzu Corporation, First Edition: September 2023