Nicotine in E-liquids

Importance of the Topic

Electronic cigarettes and vaping products have rapidly gained acceptance as alternatives to conventional tobacco products. Accurate measurement of nicotine content in e-liquids is critical for product safety, regulatory compliance, and consumer information. Potentiometric titration offers a cost-effective route to validate nicotine levels, ensuring consistent dosing and quality control.

Objectives and Study Overview

This study aims to establish and validate a simple potentiometric titration method to quantify nicotine in e-liquids and their raw nicotine preparations. Key objectives include:

• Assessing the method’s precision and accuracy
• Eliminating complex sample preparation steps
• Demonstrating applicability across various e-liquid formulations

Methodology and Instrumentation

Nicotine samples and e-liquids are directly titrated without prior extraction. The procedure involves:

• Dissolution of a measured sample mass in deionized water
• Potentiometric titration with standardized hydrochloric acid
• Detection of the equivalence point using a combined pH electrode

Instrumentation used:

• 905 Titrando potentiometric titrator
• 802 rod stirrer and 804 Ti Stand for sample agitation
• Unitrode easyClean pH electrode with integrated temperature sensor
• OMNIS/tiamo software for data acquisition and evaluation

Main Results and Discussion

All titrations produced sharp, well-defined endpoints and highly reproducible data. Representative nicotine concentrations and relative standard deviations (RSD) for multiple e-liquids and the raw nicotine material were:

• Raw nicotine: 31.39 g/L, RSD 0.03 %
• E-liquid samples: concentrations ranged from 2.82 to 15.32 g/L, RSD ≤ 0.53 %

The low variability underscores the method’s reliability and suitability for routine quality control.

Benefits and Practical Applications

This potentiometric titration approach is distinguished by its affordability, minimal chemical usage, and lack of extensive sample preparation. Laboratories can integrate this method for:

• Quality assurance in e-liquid manufacturing
• Regulatory compliance testing
• Batch-to-batch consistency checks

Future Trends and Potential Uses

The method’s simplicity makes it amenable to further automation and high-throughput workflows. Future developments may include integration with online titration platforms and adaptation for related alkaloid analyses in diverse matrices.

Conclusion

Potentiometric titration represents a practical, accurate, and cost-effective technique for nicotine quantification in e-liquids. Its robustness and ease of use position it as a valuable tool for routine analytical testing in both research and industrial settings.