Determination of nicotine, propylene glycol, and glycerol in e-liquids according to ISO/CD 20714 using an Agilent Intuvo 9000 GC

Importance of the Topic

Precise quantification of nicotine, propylene glycol and glycerol in e-liquids is essential for regulatory compliance, product safety and quality control. It ensures correct labeling under EU and ISO standards and supports consumer protection and manufacturing consistency.

Aims and Study Overview

This study evaluates a standard and a high-throughput GC-FID method based on ISO/CD 20714 for measuring nicotine, propylene glycol, and glycerol in e-liquids. It compares performance on an Agilent Intuvo 9000 system versus a conventional Agilent 7890B GC, focusing on linearity, sensitivity, repeatability and analysis speed.

Methodology

Calibration solutions at five concentration levels plus a blank were prepared in isopropanol using 1,4-butanediol and quinaldine as internal standards. The draft ISO method employed a DB-BAC1 Ultra Inert column under standard temperature programming. A fast method leveraged Intuvo 9000’s rapid heating and cooling to shorten analysis time and increase sample throughput.

Instrumentation

• Agilent Intuvo 9000 GC with flame ionization detector and Intuvo Guard Chip
• Agilent 7890B GC with split/splitless inlet and FID
• Agilent 7693 ALS with 10 μL syringe
• DB-BAC1 Ultra Inert column (30 m × 0.32 mm, 1.8 μm)

Main Results and Discussion

Both methods achieved excellent linearity (R² > 0.999), sensitivity and repeatability (RSD < 1% for glycols, < 2% for nicotine). The standard method provided clear separation in around 10 minutes. The fast method reduced run-to-run time to under five minutes with similar chromatographic resolution and even higher peak response.

Practical Benefits and Applications

• Regulatory compliance with ISO/CD 20714 and EU limits on nicotine content
• High throughput analysis suitable for routine quality control
• Robustness ensured by inert flow path and guard chip, preventing analyte degradation
• Comparable performance to conventional GC systems, facilitating method transfer

Future Trends and Potential Applications

Emerging trends include integration of rapid screening methods in manufacturing, further reduction of cycle times using fast GC technologies, and expanded panels to cover flavor additives and contaminants. Coupling with mass spectrometry could enhance selectivity for complex matrices.

Conclusion

The Agilent Intuvo 9000 GC-FID system, using a dedicated Ultra Inert DB-BAC1 column, delivers accurate, precise and rapid quantification of key e-liquid constituents in line with ISO draft standards. The high-throughput method in particular offers significant time savings without compromising performance.

Reference

• European Commission. Report on risks of refillable electronic cigarettes. COM(2016)269.
• Directive 2014/40/EU on tobacco products. OJ L127/1.
• ISO/CD 20714. E-liquid determination by gas chromatography.
• Sandy C. Qualitative analysis of e-cigarette liquids using GC/MS. Agilent 2015.