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:
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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)
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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
- R&D teams formulating detergents, emulsifiers and industrial surfactants
- Third‑party testing labs performing compliance and batch-release testing
- Procurement and specification engineers who require standardized analytical results for technical sodium alkylarylsulphonates
Practical benefits include harmonized test results, clear guidance on solvent extraction and salting‑out techniques, and comparable purity and impurity profiling across suppliers.
Related standards
Keywords: ISO 1104:1977, sodium alkylarylsulphonates, surface active agents, analytical methods, Karl Fischer, salting out, 2‑propanol, light petroleum, water content, pH measurement.