Overview
EN ISO 20714:2021 / ISO 20714:2019 specifies a validated analytical procedure for quantifying nicotine, propylene glycol (PG) and glycerol in e-liquids used with electronic nicotine delivery devices (ENDDs) using a gas chromatographic method (GC-FID). The standard defines sample preparation, required reagents and apparatus, calibration practice, chromatographic conditions, and reporting to ensure consistent, comparable results across testing laboratories.
Key topics and technical requirements
- Scope and principle
- Quantification by capillary gas chromatography with flame ionization detection (GC-FID) using internal standards.
- Reagents and standards
- High-purity carrier/auxiliary gases (helium or hydrogen; FID hydrogen and air).
- Solvent: isopropanol (≥99%) for dilution.
- Reference substances: nicotine (≥98%), propylene glycol (≥99%), glycerol (≥99%).
- Internal standards suggested: quinaldine, 1,3-butanediol, n‑heptadecane, n‑octadecane (users may assess alternatives).
- Calibration
- At least five calibration solutions covering expected analyte ranges (example ranges used in the collaborative study: nicotine 0.005–1.5 mg/ml; PG and glycerol 0.12–10 mg/ml).
- Apparatus and column
- Capillary GC with FID; DB‑ALC1 (30 m × 0.32 mm ID, 1.8 µm) cited as satisfactory. Alternative columns allowed if resolution is adequate.
- Sample handling and procedure
- Typical test portion: 0.100 g sample diluted with 10 ml isopropanol/internal standard solution; equilibrate to room temperature; store extracts at 2–8 °C if necessary.
- Example GC conditions provided (oven temperature program, injection volume 1 µl, split 50:1, helium carrier 1.8 ml/min, detector/injection temperatures).
- Quality
- Monitor internal standard peak consistency; perform repeatability and reproducibility assessments and report results per the standard.
Practical applications
- Routine laboratory testing for e-liquid composition and quality control.
- Regulatory compliance testing and product labelling verification (nicotine strength claims).
- Research and product development (formulation verification, stability studies).
- Forensic and public health labs assessing exposure potential from ENDD products.
Who should use this standard
- Analytical and contract testing laboratories performing e-liquid analysis.
- E-liquid and electronic cigarette manufacturers implementing QC procedures.
- Regulatory authorities and notified bodies overseeing product safety and compliance.
- Research institutions studying aerosol chemistry and nicotine delivery.
Related standards and references
- ISO 13276 (noted in EN ISO 20714 for verifying nicotine purity).
- Developed by ISO/TC 126 (Tobacco and tobacco products) and adopted by CEN/TC 437 (Electronic cigarettes and e-liquids).
Keywords: EN ISO 20714, ISO 20714, e-liquid analysis, gas chromatographic method, GC‑FID, nicotine determination, propylene glycol, glycerol, e-liquids testing, electronic nicotine delivery devices.