Analysis of E-Cigarette Liquid by 7890 GC and Intuvo 9000 Using an Agilent J&W DB-HeavyWAX GC Column

Importance of the Topic

E-cigarette usage and the diversity of flavor additives necessitate reliable analytical methods to ensure product quality, regulatory compliance, and user safety. Gas chromatography offers a robust platform for separating and quantifying volatile and semi-volatile constituents in e-cigarette liquids, including high-boiling flavor compounds that challenge traditional column phases.

Objectives and Study Overview

This study evaluates the Agilent J&W DB-HeavyWAX GC column on both an Agilent 7890 GC and an Agilent Intuvo 9000 GC for analyzing commercial e-cigarette liquids. Goals include assessing thermal stability for later-eluting compounds, demonstrating method equivalence across instruments, and exploring high-throughput potential via rapid temperature ramping.

Methodology and Instrumentation

Sample Preparation:

• Dilution of commercial e-cigarette liquids 10:1 in isopropanol
• Split-mode injection (50:1) at 250 °C

Chromatographic Conditions:

• DB-HeavyWAX column (60 m × 0.25 mm × 0.25 µm) on 7890 GC; DB-HeavyWAX Intuvo module (30 m × 0.25 mm × 0.25 µm) on Intuvo 9000
• Helium carrier at 2.0 mL/min, constant flow
• Temperature program: 60 °C hold 2 min; ramp 10 °C/min to 250 °C (15 min); optional extension to 280 °C or 290 °C; fast ramp of 250 °C/min on Intuvo

Instrumentation Details:

• Agilent 7890 GC with split/splitless inlet, 7693 autosampler, 5977 MSD/FID detector
• Agilent Intuvo 9000 GC/FID with planar column module, guard/flow chips, 7693 autosampler, 5977 MSD

Main Results and Discussion

Separation of Flavor A and B formulations resolved key constituents including propylene glycol, glycerol, nicotine, esters, terpenoids, and flavor aldehydes. The DB-HeavyWAX column exhibited low bleed (4 pA) at 280 °C and only 10.5 pA at 290 °C, demonstrating enhanced thermal stability. Comparative runs on the 7890 and Intuvo 9000 showed virtually identical retention times and peak intensities, confirming method equivalence. Employing the Intuvo’s fast 250 °C/min ramp reduced total analysis time to under six minutes without compromising resolution.

Benefits and Practical Applications

• Extended thermal range reduces carryover of high-boiling flavor compounds
• Low column bleed enhances detection sensitivity for trace analytes
• Consistency across GC platforms supports reliable cross-laboratory results
• Rapid temperature cycling enables high-throughput QC screening

Future Trends and Opportunities

Anticipated advancements include coupling with tandem MS for improved compound identification, further miniaturization of GC instrumentation, automated sample handling for large-scale screening, and development of novel stationary phases to accommodate emerging vaping formulations.

Conclusion

The Agilent J&W DB-HeavyWAX column, used with either the 7890 GC or the Intuvo 9000 GC, provides a robust, high-throughput solution for comprehensive e-cigarette liquid analysis. Its increased thermal stability, low bleed profile, and compatibility with rapid temperature ramps ensure reliable detection of both primary solvents and diverse flavor additives.

References

1. Sandy C. Qualitative analysis of e-cigarette liquids using gas chromatography/mass spectrometry. Agilent Technologies Application Note 5991-6412EN (2015).
2. David F., D’Haenens B., Devos C. Determination of nicotine, propylene glycol, and glycerol in e-liquids according to ISO/CD 20714 using an Agilent Intuvo 9000. Agilent Technologies Application Note 5991-8990EN (2018).
3. Abercrombie V., Provoost L. Increased thermal stability and maximum temperature of the Agilent J&W DB-HeavyWAX column. Agilent Technologies Application Note 5991-9035EN (2018).