Overview
EN ISO 2871-1:2010 (ISO 2871-1:2010) specifies a validated laboratory method for the determination of high‑molecular‑mass cationic‑active matter in detergents and surface‑active agent formulations. It covers quaternary ammonium compounds where two alkyl groups have ≥10 carbon atoms (e.g., distearyl‑dimethyl‑ammonium chlorides) and certain imidazoline‑based salts. The procedure applies to solids and aqueous solutions when the relative molecular mass of the cationic material is known or previously determined. The method is not applicable if anionic surfactants are present.
Key topics and technical requirements
- Analytical principle: direct two‑phase titration - titration of a standard sodium lauryl sulfate solution with the test sample (referencing ISO 2271).
- Reagents: chloroform, propan‑2‑ol (isopropanol), a standard sodium lauryl sulfate solution and a mixed indicator (as specified in ISO 2271).
- Apparatus: ordinary laboratory glassware plus class A burette and one‑mark 1 000 ml volumetric flask (ISO 385, ISO 1042).
- Sample preparation: dissolve weighed test portion in propan‑2‑ol, dilute to 1 000 ml with water to prepare the titrant solution.
- Titration procedure: titrate 10 ml of the sodium lauryl sulfate standard against the prepared test solution; observe colour changes in the chloroform phase to identify end point.
- Expression of results: cationic content reported as percentage by mass, calculated from titration volume, SLS concentration, sample mass and the relative molecular mass of the cationic species.
- Performance characteristics: repeatability limit ≈ 1.5% of the mean; reproducibility limit ≈ 3% of the mean.
- Limitations and interferences: method tolerates certain non‑ionic agents and common inorganic detergent ingredients; it fails in presence of anionic surfactants. Some hydrotropes or bleaching agents may require evaluation or destruction prior to analysis.
Applications and who uses this standard
- Quality control and formulation testing in detergent, textile, household‑care and personal‑care manufacturing.
- Analytical and regulatory laboratories verifying cationic surfactant content for labelling, compliance and batch release.
- R&D groups characterizing high‑molecular‑mass quaternary ammonium compounds and imidazoline derivatives.
- Standards committees and testing service providers adopting a harmonized titration method for consistent reporting.
Keywords: EN ISO 2871-1:2010, ISO 2871-1:2010, determination of cationic-active matter, high-molecular-mass cationic-active matter, detergents, surface active agents, direct two-phase titration, sodium lauryl sulfate.
Related standards
- ISO 2271 - Determination of anionic‑active matter (direct two‑phase titration)
- ISO 607 - Sample division for surface active agents
- ISO 385, ISO 1042 - Laboratory glassware specifications
- ISO 2871‑2 - Cationic‑active matter of low molecular mass (200–500)
