Overview
ISO 15152:2003 - "Tobacco - Determination of the content of total alkaloids as nicotine - Continuous-flow analysis method" - specifies a laboratory procedure to quantify total alkaloids expressed as nicotine in manufactured and unmanufactured tobacco using a continuous‑flow analyser. The method uses an aqueous (or 5% acetic acid) extract of ground tobacco, chemical derivatization with sulfanilic acid and in‑situ generated cyanogen chloride, and colorimetric detection at 460 nm to determine nicotine-equivalent alkaloid content.
Key topics and technical requirements
- Scope: Applicable to both manufactured and unmanufactured tobacco.
- Sample preparation: Grind tobacco to pass a 1 mm sieve, determine moisture, typically weigh ~250 mg and extract with 25 mL water (or 5% acetic acid) with 30 min shaking.
- Analytical principle: Nicotine/total alkaloids react with sulfanilic acid after cyanogen chloride generation (from KCN + chloramine T or alternative reagents) to produce a coloured product measured at 460 nm using a continuous‑flow system.
- Instrumentation: Continuous‑flow analyser components include sampler, proportioning pump, dialyser, delay coils, 460 nm colorimeter and recorder. Annex B in the standard gives an example layout.
- Calibration and calculation: Use nicotine hydrogen tartrate standards to prepare working standards (e.g., 0.04–0.80 mg/mL). Determine nicotine-equivalent concentration from a calibration curve and calculate percent nicotine on a dry-weight basis using extract volume, sample mass and measured moisture.
- Safety & waste: Potassium cyanide and cyanogen chloride are hazardous. ISO 15152 mandates strict safety measures, neutralizing procedures (cyanide neutralizing solutions A and B), and an on-line destruction apparatus for cyanogen chloride waste.
- Performance: The standard reports repeatability and reproducibility results from collaborative studies; values vary by tobacco type and extraction solvent (water vs 5% acetic acid).
Applications and who uses it
- Quality control labs in tobacco manufacturing for routine monitoring of alkaloid content.
- Analytical and research laboratories performing comparative alkaloid profiling and method validation.
- Regulatory and compliance bodies requiring standardized nicotine/alkaloid reporting.
- Contract testing facilities providing accredited measurement services.
Practical benefits include reproducible quantification of total alkaloids expressed as nicotine, compatibility with simultaneous tests (reducing substances, reducing carbohydrates, nitrates when 5% acetic acid is used), and suitability for high-throughput continuous‑flow analysis.
Related standards (if applicable)
- ISO 13276 - determination of nicotine purity
- ISO 15153 - reducing substances in tobacco
- ISO 15154 - reducing carbohydrates in tobacco
- ISO 15517 - nitrates in tobacco
- ISO 2881 - alternative alkaloid determination methods (CORESTA-related)
Keywords: ISO 15152:2003, tobacco alkaloids, nicotine determination, continuous‑flow analysis, tobacco testing, laboratory method, CORESTA.