ISO 6843:1988

Overview

ISO 6843:1988 is an international standard published by the International Organization for Standardization (ISO) that specifies a well-defined analytical method for the estimation of the mean relative molecular mass of anionic-active matter present in commercial neutralized products derived from the sulfation of ethoxylated alcohols or alkylphenols. This standard is applicable to products containing an average of up to 20 oxyethylene groups per molecule, often known as alkyl oxyethylene sulfates (ethoxylated alcohol sulfates) and alkylphenol oxyethylene sulfates (ethoxylated alkylphenol sulfates).

The method described relies on systematic steps including extraction, separation, evaporation, redissolution, and filtration using ion-exchange resins. Through this process, the contents of sodium chloride, anionic-active matter, polyglycol, and polyglycol sulfate are determined to provide an accurate estimation of the mean relative molecular mass.

Key Topics

• Surface Active Agents: Focuses on anionic surfactants such as sulfated ethoxylated alcohols and alkylphenols widely used in cleaning and detergent industries.
• Molecular Mass Estimation: Provides a standardized procedure for estimating the mean relative molecular mass, important for product characterization.
• Sequential Analytical Procedures:
  • Extraction of anionic-active matter using an ethyl acetate/butan-1-ol mixture
  • Evaporation and redissolution of the aqueous phase to separate other components
  • Removal of salts and further isolation of polyglycol and polyglycol sulfate via ion-exchange chromatography
• Calculation Methods: Utilizes content data derived from direct titrations and calculations standardized within ISO methods.
• Sample Preparation and Handling: Emphasizes correct sampling, storage, and the use of analytical-grade reagents and glassware compliant with related ISO standards.

Applications

ISO 6843:1988 is highly relevant for:

• Quality Control in Manufacturing: Manufacturers use this standard to ensure product consistency and compliance, especially for surface-active agents in detergents, cleaners, and personal care products.
• Product Certification and Regulatory Compliance: Meeting the molecular mass requirements specified in various regulations or certifications.
• Research and Development: Laboratories involved in developing new surfactant formulations or evaluating alternative raw materials benefit from standardized assessment procedures.
• Analytical Services: Third-party laboratories offering testing or certification services for chemical ingredients leverage this standard to provide reliable, repeatable results for their clients.

By following ISO 6843:1988, users gain confidence in the accuracy and comparability of molecular mass estimation, which is essential for the performance and labeling of surfactant-based products.

Related Standards

For comprehensive and accurate implementation of ISO 6843:1988, the following related ISO standards are referenced and recommended:

• ISO 607:1980 - Surface active agents and detergents – Methods of sample division
• ISO 1042:1983 - Laboratory glassware – One-mark volumetric flasks
• ISO 2271:1972 - Surface active agents – Detergents – Determination of anionic-active matter (direct two-phase titration procedure)
• ISO 4800:1977 - Laboratory glassware – Separating funnels and dropping funnels
• ISO 6842:1983 - Surface active agents – Polyethoxylated alcohol and alkylphenol sulfates – Determination of total active matter
• ISO 8799:1988 - Sulfated ethoxylated alcohols and alkylphenols – Determination of content of unsulfated matter

Adopting ISO 6843:1988 ensures robust, internationally recognized procedures for the estimation of mean relative molecular mass in surfactant products, supporting product quality, regulatory compliance, and market acceptance.