ISO 6122:1978

Overview

ISO 6122:1978 is an international standard published by the International Organization for Standardization (ISO) that specifies a precise method for determining the total alkane sulphonates content in technical alkane sulphonates, which are surface active agents. This standard focuses on analyzing both mono- and di-alkane sulphonates in products derived from the sulphochlorination and sulphoxidation of paraffins with carbon chain lengths typically between 12 and 20 atoms. The method addresses samples containing minor amounts of paraffins and involves a combination of gravimetric and potentiometric techniques to ensure accurate quantification.

Key Topics

• Scope and Application
  Applicable to alkali metal salts of alkane sulphonates used as surfactants, particularly those from technical paraffin derivatives. This method helps determine product purity by measuring total alkane sulphonate content and detecting contaminating sodium chloride.

• Analytical Principle
  The test involves dispersing a sample in a sodium sulfate solution, followed by the addition of a butan-1-ol and acetone mixture. This causes sodium sulfate decahydrate and some sodium chloride to precipitate. The resulting mixture of alkane sulphonates is filtered, solvents are evaporated to remove paraffinic impurities, and the total alkane sulphonates are gravimetrically measured. Remaining sodium chloride is then quantified potentiometrically.

• Reagents and Equipment
  Requires recognized analytical grade reagents such as acetone, a mixture of butan-1-ol and acetone (60:40 v/v), and anhydrous sodium sulfate solution. Essential apparatus includes a boiling flask or crystallizing dish, an oven capable of 120°C ± 2°C, and a magnetic stirrer to ensure homogeneous mixing.

• Sampling and Preparation
  Laboratory samples are prepared per ISO 607 guidelines to ensure representative and homogenous testing material. Test portions are typically in the range of 0.5 to 1 gram of total alkane sulphonates.

• Calculation and Reporting
  The total alkane sulphonate content is expressed as a percentage by mass, factoring in the weight of sample residues and sodium chloride content. Test reports must comprehensively detail sample identification, methods used, results, conditions, and any deviations or incidents impacting the analysis.

Applications

ISO 6122:1978 is essential for quality control and purity assessment in the production of surface active agents containing alkane sulphonates, widely used in:

• Detergent manufacturing
• Soap and cleansing products
• Emulsifiers and dispersants in industrial processes
• Chemical formulations requiring surfactants with defined purity levels

By ensuring accurate determination of alkane sulphonate content, manufacturers can optimize formulations, comply with regulatory standards, and guarantee consistent product performance.

Related Standards

• ISO 607 - Surface active agents and detergents: Methods for sample division, ensuring representative test material.
• ISO 894 - Surface active agents - Technical sodium primary alkylsulphates: Methods of analysis including potentiometric determination for sodium chloride content, referenced within ISO 6122 for sodium chloride quantification.

These interconnected standards provide a comprehensive framework for analyzing surfactant products and maintaining international quality benchmarks in the chemical industry.

Keywords: ISO 6122, alkane sulphonates, surface active agents, surfactants, gravimetric determination, sodium chloride potentiometric analysis, technical alkane sulphonates, paraffin derivatives, detergent raw materials, surfactant purity testing, international standard for alkane sulphonates.