ISO 1104:1977

Overview

ISO 1104:1977 - Surface active agents: Technical sodium alkylarylsulphonates (excluding benzene derivatives) - Methods of analysis defines standardized laboratory procedures for the chemical analysis of technical-grade sodium alkylarylsulphonates (paste or powder). The standard excludes sodium alkylbenzenesulphonates and is not applicable to liquid products that may contain solvents or additives. Annexes provide a general scheme of analysis and a rapid determination method for sodium alkylarylsulphonates.

Key topics and technical requirements

ISO 1104:1977 specifies precise analytical determinations and recommended procedures, including:

• Primary determinations

  • Measurement of pH (potentiometric method referenced to ISO 4316)
  • Water content by Karl Fischer (ISO 4317) or azeotropic distillation (ISO 4318), depending on water level
  • Free alkalinity or free acidity (titrimetric method, ISO 4314)
  • Matter extractable by light petroleum (hydrocarbon-soluble impurities)
  • Content of sodium alkylarylsulphonates using salting-out into 2‑propanol and solvent evaporation/isolation
  • Sodium sulphite (iodometric titration)
  • Sodium sulphate
  • Sodium chloride (potentiometric/argentometric approaches referenced)

• Procedural highlights

  • Sample preparation: prepare a laboratory sample ~300 g per ISO 607 sampling guidance.
  • Extraction and separation: use 2‑propanol and salting-out with anhydrous sodium carbonate to separate sodium alkylarylsulphonates from non-sulphonated material; extract impurities with light petroleum (40–60 °C boiling range).
  • Reagents and apparatus: specifies analytical-grade reagents (e.g., 2‑propanol, dioxane, anhydrous sodium sulfate) and common laboratory equipment (separating funnels, fractionating column, ovens).
  • Performance notes: reproducibility targets are provided (e.g., differences between labs for certain determinations typically ≤ 1% or ≤ 0.2% as stated).

Applications and users

ISO 1104:1977 is intended for:

• Quality control laboratories in surfactant manufacturing and chemical processing