ISO 16632:2021 PDF

Overview

ISO 16632:2021 specifies a gas‑chromatographic (GC) method for the determination of water content in tobacco and tobacco products. Applicable to raw tobacco and tobacco taken from finished products (including cigars and smokeless reference products), the method reliably measures water mass fractions from about 2 % to 55 %. The procedure uses methanolic extraction with isopropanol as an internal standard and analysis by capillary GC with a thermal conductivity detector (TCD).

Key topics and technical requirements

• Principle: Methanolic extraction of water from a defined sample portion, followed by GC‑TCD analysis with an internal standard (isopropanol).
• Scope and range: Suitable for a wide variety of tobaccos and finished products; validated for ~2–55 % water content.
• Reagents:
  • Methanol (max. 1.0 mg/ml water) - hygroscopic and toxic (safety MSDS required).
  • Isopropanol (≥99 %) as internal standard (typical addition ~2.0 ml/L).
  • Water conforming to ISO 3696 (grade 2 or better).
• Apparatus:
  • GC with thermal conductivity detector, autosampler and data system.
  • Example column: PLOT fused silica with PoraPLOT U phase (25 m × 0.53 mm).
  • Standard lab glassware, shaker and filtration (0.45 µm) supplies.
• Sample preparation:
  • Typical test portion: (5.0 ± 0.25) g sample with 100.0 ml extraction solution.
  • Shake 3 h, set aside overnight, filter supernatant (0.45 µm) and refrigerate (