Overview
ISO 22980:2020 - "Tobacco - Determination of the content of total alkaloids as nicotine - Continuous‑flow analysis method using KSCN/DCIC" specifies a validated laboratory method for measuring total alkaloids expressed as nicotine in tobacco. The method uses segmented continuous‑flow analysis with potassium thiocyanate (KSCN) and sodium dichloroisocyanurate (DCIC) to generate cyanogen chloride in situ, develop a brown colour with sulfanilic acid, and quantify the result photometrically at 460 nm. It applies to leaf tobacco, stems, reconstituted tobacco sheet materials and tobacco blends, and supports both water and 5% acetic acid extraction.
Key Topics and Requirements
- Principle: Reaction of sulfanilic acid with cyanogen chloride (generated from KSCN + DCIC) produces a measurable colour at 460 nm.
- Sample preparation: Grind tobacco to pass a 1 mm sieve, determine moisture, weigh ~250 mg test portion and extract with 25 ml water or 5% acetic acid.
- Reagents & solutions: Specifies analytical‑grade reagents (e.g., KSCN, DCIC, sulfanilic acid, nicotine ditartrate) and preparation of buffer, neutralisation and wash solutions.
- Calibration: Use nicotine ditartrate (check purity per ISO 13276) to prepare a nicotine stock (~2.5 mg/ml) and at least five working standards spanning expected concentration (e.g., 0.5–15% nicotine mass fraction).
- Apparatus: Continuous‑flow analyser with autosampler, peristaltic pump, manifold with dialyser/delay coils and a photometric detector with 460 nm filter; data acquisition/recorder.
- Quality & safety: Recommends ISO‑level water (ISO 3696), filtration/degassing of reagents, fresh daily DCIC solution, and good laboratory practice. The KSCN/DCIC approach was developed to avoid use of potassium cyanide used in older procedures.
Applications and Users
- Who uses it: tobacco industry quality control, contract analytical laboratories, regulatory testing agencies, research institutions and standards organizations performing routine nicotine/alkaloid assays.
- Why use it: Provides a reproducible, continuous‑flow analytical workflow for rapid throughput and compatibility with simultaneous analyses (e.g., reducing substances or carbohydrates when using 5% acetic acid extract). Suitable for routine monitoring, product development and compliance testing.
Related Standards
Keywords: ISO 22980:2020, tobacco testing, total alkaloids, nicotine determination, continuous‑flow analysis, KSCN, DCIC, analytical method.