Overview
ISO 8799:2009 specifies a laboratory method to determine the content of unsulfated matter in commercial neutralized sulfated ethoxylated alcohols and alkylphenols (commonly known as ethoxylated alcohol sulfates or alkylphenol sulfates) that contain an average of up to 20 oxyethylene groups per molecule. The procedure isolates unsulfated (non-ionic) components using a mixed-bed ion-exchange column, recovers them from a methanolic eluate, and quantifies them by evaporation and weighing.
Key topics and requirements
- Scope: Applies to ordinary commercial neutralized sulfation products of ethoxylated alcohols and alkylphenols (≤20 oxyethylene units).
- Principle: Separation of unsulfated matter on a mixed ion-exchange column (anion + cation resins) from a methanolic solution; residue is evaporated and weighed.
- Reagents & materials: Analytical-grade methanol, HCl, NaOH; cation-exchange resin (polystyrene sulfonic acid, H+ form) and anion-exchange resin (quaternary ammonium, Cl− form).
- Apparatus: Open glass ion-exchange column (approx. 25 mm × 200 mm), rotary evaporator, controlled water bath (≤40 °C).
- Procedure highlights:
- Resin cleaning and conditioning (base/acid washes, methanol rinses).
- Prepare mixed-bed column (typically equal volumes of cation + anion resins).
- Pass a methanolic solution of a test portion through the column (nominal flow ~2 mL/min), collect eluate, evaporate and weigh residue.
- Check column performance by titrating residue for anionic-active matter (ISO 2271 or EN 14480); repeat test if incomplete exchange is detected.
- Calculation: Unsulfated matter is expressed as percentage by mass = (mass of residue / mass of test portion) × 100.
- Precision data: Interlaboratory tests reported standard deviation of repeatability ≈ 0.18 and reproducibility ≈ 0.39 (Annex A).
Applications and who uses it
This standard is primarily used for quality control, product specification, batch release and regulatory compliance in industries producing or using anionic surfactants:
- Manufacturers of detergents, personal-care formulations and industrial surfactants
- Analytical and contract testing laboratories performing surfactant purity assays
- R&D and formulation scientists monitoring sulfation efficiency
- Regulatory and standards bodies assessing product conformity
Practical benefits include consistent measurement of unsulfated (non-ionic) impurities that can affect product performance, stability and regulatory labeling.
Related standards
- ISO 2271 - Determination of anionic-active matter by two‑phase titration
- EN 14480 - Potentiometric two‑phase titration for anionic surfactants
- ISO 607 - Sample division for surface active agents
- ISO 3696 - Water for analytical laboratory use
- ISO 6842 - Determination of total active matter for sulfated ethoxylated alcohols
Keywords: ISO 8799, unsulfated matter, sulfated ethoxylated alcohols, alkylphenol sulfates, ion-exchange column, surface active agents, anionic-active matter, mixed-bed ion exchange, surfactant quality control.